The goal of this exercise is to make you familiar with how to download data from Google Sheets and to briefly review some key concepts R functions and coding concepts.

We’ll do the following things

-DOWNLOAD A LIST OF REFSEQ ACCESSIONS FROM A GOOGLE SHEET -REMOVE THE NAS USING NA.OMIT -SELECT OUT ALL BUT ONE ISOFORM USING DUPLICATED

Packages

## Google sheets download package
# comment this out when you are done
# install.packages("googlesheets4")
library(googlesheets4)

# comp bio packages
library(seqinr)
library(rentrez)
library(compbio4all)
library(Biostrings)
## Loading required package: BiocGenerics
## Loading required package: parallel
## 
## Attaching package: 'BiocGenerics'
## The following objects are masked from 'package:parallel':
## 
##     clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
##     clusterExport, clusterMap, parApply, parCapply, parLapply,
##     parLapplyLB, parRapply, parSapply, parSapplyLB
## The following objects are masked from 'package:stats':
## 
##     IQR, mad, sd, var, xtabs
## The following objects are masked from 'package:base':
## 
##     anyDuplicated, append, as.data.frame, basename, cbind, colnames,
##     dirname, do.call, duplicated, eval, evalq, Filter, Find, get, grep,
##     grepl, intersect, is.unsorted, lapply, Map, mapply, match, mget,
##     order, paste, pmax, pmax.int, pmin, pmin.int, Position, rank,
##     rbind, Reduce, rownames, sapply, setdiff, sort, table, tapply,
##     union, unique, unsplit, which.max, which.min
## Loading required package: S4Vectors
## Loading required package: stats4
## 
## Attaching package: 'S4Vectors'
## The following objects are masked from 'package:base':
## 
##     expand.grid, I, unname
## Loading required package: IRanges
## Loading required package: XVector
## Loading required package: GenomeInfoDb
## 
## Attaching package: 'Biostrings'
## The following object is masked from 'package:seqinr':
## 
##     translate
## The following object is masked from 'package:base':
## 
##     strsplit

Download data

URL ADDRESS FOR THE SPREADSHEET WITH THE DATA

spreadsheet_sp <- "https://docs.google.com/spreadsheets/d/1spC_ZA3_cVuvU3e_Jfcj2nEIfzp-vaP7SA5f-qwQ1pg/edit?usp=sharing" 

SECONDLE WE NEED TO MAKE SURE WE TELL THE PACKAGE WE AREN’T INTERESTED IN CHECKING USER ACCESS CREDENTIALS/ AUTHORIZATION

# be sure to run this!
googlesheets4::gs4_deauth()   # <====== MUST RUN THIS

DOWNLOAD DATA

NOTE!: sometimes Google Sheets or the function gets cranky and throws this error:

“Error in curl::curl_fetch_memory(url, handle = handle) : Error in the HTTP2 framing layer”

If that happens, just re-run the code.

# I include this again in case you missed is the first time : )
googlesheets4::gs4_deauth()  

# download
## NOTE: if you get an error, just run the code again
refseq_column <- read_sheet(ss = spreadsheet_sp, # the url
           sheet = "RefSeq_prot",                # the name of the worksheet
           range = "selenoprot!H1:H364",
           col_names = TRUE,
           na = "",                           # fill in empty spaces "" w/ NA
           trim_ws = TRUE)
## ✓ Reading from "human_gene_table".
## ✓ Range ''selenoprot'!H1:H364'.
## NOTE: if you get an error, just run the code again

# for reasons we won't get into I'm going to do this
protein_refseq <- refseq_column$RefSeq_prot

Gives us the first 10 protein accession numbers from the SPREADSHEET with NAs removed

protein_refseq[1:10]
##  [1] "NP_000783.2"    "NP_998758.1"    "NP_001034804.1" "NP_001034805.1"
##  [5] "NP_001311245.1" NA               NA               "NP_054644.1"   
##  [9] "NP_001353425.1" "NP_000784.3"

LETS GET ANOTHER COLUMN

# download
## NOTE: if you get an error, just run the code again
gene_name_column <- read_sheet(ss = spreadsheet_sp, # the url
           sheet = "gene",                # the name of the worksheet
           range = "selenoprot!A1:A364",
           col_names = TRUE,
           na = "",                              # fill in empty spaces "" w/NA
           trim_ws = TRUE)
## ✓ Reading from "human_gene_table".
## ✓ Range ''selenoprot'!A1:A364'.
## NOTE: if you get an error, just run the code again

# for reasons we won't get into I'm going to do this
gene <- gene_name_column$gene

Check Data

GIVES WHAT TYPE OF DATA THE VECTOR IS, HOW MANY ACCESSIONS THERE ARE, AND THE FIRST 10 ACCESSIONS

is(protein_refseq)
##  [1] "character"               "vector"                 
##  [3] "data.frameRowLabels"     "SuperClassMethod"       
##  [5] "character_OR_connection" "character_OR_NULL"      
##  [7] "atomic"                  "EnumerationValue"       
##  [9] "vector_OR_Vector"        "vector_OR_factor"
class(protein_refseq)
## [1] "character"
length(protein_refseq)
## [1] 363
protein_refseq[1:10]
##  [1] "NP_000783.2"    "NP_998758.1"    "NP_001034804.1" "NP_001034805.1"
##  [5] "NP_001311245.1" NA               NA               "NP_054644.1"   
##  [9] "NP_001353425.1" "NP_000784.3"

CHECK FOR PRESENCES OF NAS USING IS.NA (EITHER PROTEIN ACCESSION NOT ENTERED YET, OR WRONG ACCESSION TYPED)

is.na(protein_refseq)
##   [1] FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE FALSE FALSE FALSE FALSE  TRUE
##  [13]  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE FALSE
##  [25] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE FALSE FALSE
##  [37] FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [49] FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [61] FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE
##  [73]  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE
##  [85] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [97] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [109] FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [121]  TRUE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE
## [133] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [145] FALSE FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE
## [157] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [169] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [181] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [193] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE FALSE
## [205] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [217] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [229] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [241] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE
## [253] FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [265] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [277] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE
## [289]  TRUE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [301] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [313] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [325] FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE
## [337] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [349] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [361] FALSE FALSE FALSE

TABULATE THE FALSE/TRUE DATA (FALSE MEANS NOT AN “NA” )

table(is.na(protein_refseq))
## 
## FALSE  TRUE 
##   334    29

Giving us the number of genes that do not have an accession entered

# get TRUE/FALSE
temp <- is.na(protein_refseq)

# this subsets by the TRUE statements
protein_refseq[temp]
##  [1] NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
## [26] NA NA NA NA
temp2 <- protein_refseq[temp]

# count them up
length(temp2)
## [1] 29

Make a dataframe

2D DATA STRUCTURE (DATAFRAME) OF EACH GENE AND ITS PROTEIN REFSEQ NUMBER

seleno_df <- data.frame(gene = gene,
                        protein_refseq = protein_refseq)

SUMMARY STATISTICS + FIRST 6 ROWS IN THE DATAFRAME

summary(seleno_df)
##      gene           protein_refseq    
##  Length:363         Length:363        
##  Class :character   Class :character  
##  Mode  :character   Mode  :character
head(seleno_df)
##   gene protein_refseq
## 1 DIO1    NP_000783.2
## 2 DIO1    NP_998758.1
## 3 DIO1 NP_001034804.1
## 4 DIO1 NP_001034805.1
## 5 DIO1 NP_001311245.1
## 6 DIO1           <NA>

Removing NAs

REMOVING ALL THE ROWS THAT DO NOT HAVE REF_SEQPROT ACCESSIONS

# omit NAs
seleno_df_noNA <- na.omit(seleno_df)

# check length- should be shorter
dim(seleno_df)
## [1] 363   2
dim(seleno_df_noNA)
## [1] 334   2

Select just 1 isoform

The same gene can appear multiple times because multiple isoforms are listed.

head(seleno_df_noNA)
##   gene protein_refseq
## 1 DIO1    NP_000783.2
## 2 DIO1    NP_998758.1
## 3 DIO1 NP_001034804.1
## 4 DIO1 NP_001034805.1
## 5 DIO1 NP_001311245.1
## 8 DIO2    NP_054644.1

GIVES US THE UNIQUE GENES WITHOUT THE DUPLICATES DUE TO MULTIPLE ISOFORMS, SELECTS ONE ROW FOR EACH GENE

genes_unique <- unique(seleno_df_noNA$gene)
length(genes_unique)
## [1] 37
genes_unique
##  [1] "DIO1"     "DIO2"     "DIO3"     "GPX1"     "GPX2"     "GPX3"    
##  [7] "GPX4"     "GPX6"     "MSRB1"    "SELENOF"  "SELENOH"  "SELENOI" 
## [13] "SELENOK"  "SELENOM"  "SELENON"  "SELENOO"  "SELENOP"  "SELENOS" 
## [19] "SELENOT"  "SELENOV"  "SELENOW"  "SEPHS2"   "TXNRD1"   "TXNRD2"  
## [25] "TXNRD3"   "SELENOP1" "SELENOP2" "SELENOU"  "SELENOW1" "SELENOW2"
## [31] "SELENOE"  "SELENOJ"  "SELENOL"  "SELENOO1" "SELENOO2" "SELENOT1"
## [37] "SELENOT2"

unique() just gives us the unique elements. A related function, duplicated(), gives us the location of duplicated elements in the vector. FALSE means “not duplicated yet” or “first instance so far”.

i.dups <- duplicated(seleno_df_noNA$gene)

We can remove the duplicates using a form of reverse indexing where the “!” means “not”. (You don’t need to know this for the exam)

seleno_df_noNA[!i.dups, ]
##         gene protein_refseq
## 1       DIO1    NP_000783.2
## 8       DIO2    NP_054644.1
## 14      DIO3    NP_001353.4
## 15      GPX1    NP_000572.2
## 20      GPX2    NP_002074.2
## 24      GPX3    NP_002075.2
## 26      GPX4    NP_002076.2
## 29      GPX6    NP_874360.1
## 30     MSRB1    NP_057416.1
## 31   SELENOF    NP_004252.2
## 35   SELENOH    NP_734467.1
## 37   SELENOI    NP_277040.1
## 39   SELENOK    NP_067060.2
## 40   SELENOM    NP_536355.1
## 41   SELENON    NP_996809.1
## 43   SELENOO    NP_113642.1
## 44   SELENOP    NP_005401.3
## 47   SELENOS    NP_060915.2
## 49   SELENOT    NP_057359.2
## 50   SELENOV    NP_874363.1
## 53   SELENOW    NP_003000.1
## 54    SEPHS2    NP_036380.2
## 55    TXNRD1    NP_877393.1
## 62    TXNRD2    NP_006431.2
## 69    TXNRD3    NP_443115.1
## 232 SELENOP1 NP_001026780.2
## 233 SELENOP2 NP_001335698.1
## 236  SELENOU NP_001180447.1
## 268 SELENOW1 NP_001291715.2
## 269 SELENOW2 NP_001341647.1
## 334  SELENOE NP_001182713.2
## 338  SELENOJ NP_001180398.1
## 340  SELENOL NP_001177311.1
## 343 SELENOO1 NP_001038336.2
## 344 SELENOO2 NP_001335014.1
## 348 SELENOT1    NP_840075.2
## 350 SELENOT2 NP_001091957.2

Make a dataframe of non-duplicated genes

seleno_df_noDups <- seleno_df_noNA[!i.dups, ]
dim(seleno_df_noDups)
## [1] 37  2

Select 2 random sequences

Let’s select 2 random sequences to work with. We’ll use WHICH FUNCTION? to select a random index number to get - SAMPLE()

First, lets make a vector that contains a unique number for each row of data

indices <- 1:nrow(seleno_df_noDups)

This would do the same thing

# with dim
indices <- 1:dim(seleno_df_noDups)[1]

# with length
indices <- 1:length(seleno_df_noDups$gene)

or hard-coded

indices <- 1:37

We can then use SAMPLE() to select 2 random numbers from this vector.

For x = we’ll use our vector of indices (1 to 37). For size we’ll use 2, since we want to pull out just 2 numbers. For replace we’ll use FALSE since we don’t want to be ale to select the same number twice.

i.random.genes <- sample(x = indices,
                         size = 2,
                         replace = FALSE)

Hard coded this would be

i.random.genes <- sample(x = c(1:37),
                         size = 2,
                         replace = FALSE)

This gives me TWO indices values.

i.random.genes
## [1] 29  7

I can now use these index values to pull out 2 rows of data

seleno_df_noNA[i.random.genes, ]
##       gene protein_refseq
## 39 SELENOK    NP_067060.2
## 9     DIO2 NP_001353425.1

Hard coded, this would be something like this for whichever genes happen to have been selected

seleno_df_noNA[c(37,15), ]
##       gene protein_refseq
## 47 SELENOS    NP_060915.2
## 19    GPX1 NP_001316384.1

Downloading genes

I will now DOWNLOAD 2 FASTA FILES

rentrez::entrez_fetch(id = "NP_060915.2",
                      db = "protein",
                      rettype = "fasta")
## [1] ">NP_060915.2 selenoprotein S isoform 1 [Homo sapiens]\nMERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQRQLDRAAAAV\nEPDVVVKRQEALAAARLKMQEELNAQVEKHKEKLKQLEEEKRRQKIEMWDSMQEGKSYKGNAKKPQEEDS\nPGPSTSSVLKRKSDRKPLRGGGYNPLSGEGGGACSWRPGRRGPSSGGUG\n\n"
rentrez::entrez_fetch(id = "NP_001316384.1",
                      db = "protein",
                      rettype = "fasta")
## [1] ">NP_001316384.1 glutathione peroxidase 1 isoform 5 [Homo sapiens]\nMCAARLAAAAAAAQSVYAFSARPLAGGEPVSLGSLRGKENAKNEEILNSLKYVRPGGGFEPNFMLFEKCE\nVNGAGAHPLFAFLREALPAPSDDATALMTDPKLITWSPVCRNDVAWNFEKFLVGPDGVPLRRYSRRFQTI\nDIEPDIEALLSQGPSCA\n\n"

SAVE THE FASTA FILES INTO TWO VECTORS

prot1 <- rentrez::entrez_fetch(id = "NP_060915.2",
                      db = "protein",
                      rettype = "fasta")

prot2 <- rentrez::entrez_fetch(id = "NP_001316384.1",
                      db = "protein",
                      rettype = "fasta")

I can put them into a LIST like this

# make the LIST
seleno_thingy <- vector("list", 1)


# add the first fasta
seleno_thingy[[1]] <- prot1

# See the result
seleno_thingy
## [[1]]
## [1] ">NP_060915.2 selenoprotein S isoform 1 [Homo sapiens]\nMERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQRQLDRAAAAV\nEPDVVVKRQEALAAARLKMQEELNAQVEKHKEKLKQLEEEKRRQKIEMWDSMQEGKSYKGNAKKPQEEDS\nPGPSTSSVLKRKSDRKPLRGGGYNPLSGEGGGACSWRPGRRGPSSGGUG\n\n"
# add the first fasta
seleno_thingy[[2]] <- prot2

# see the result
seleno_thingy
## [[1]]
## [1] ">NP_060915.2 selenoprotein S isoform 1 [Homo sapiens]\nMERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQRQLDRAAAAV\nEPDVVVKRQEALAAARLKMQEELNAQVEKHKEKLKQLEEEKRRQKIEMWDSMQEGKSYKGNAKKPQEEDS\nPGPSTSSVLKRKSDRKPLRGGGYNPLSGEGGGACSWRPGRRGPSSGGUG\n\n"
## 
## [[2]]
## [1] ">NP_001316384.1 glutathione peroxidase 1 isoform 5 [Homo sapiens]\nMCAARLAAAAAAAQSVYAFSARPLAGGEPVSLGSLRGKENAKNEEILNSLKYVRPGGGFEPNFMLFEKCE\nVNGAGAHPLFAFLREALPAPSDDATALMTDPKLITWSPVCRNDVAWNFEKFLVGPDGVPLRRYSRRFQTI\nDIEPDIEALLSQGPSCA\n\n"
# WHAT DOES THIS DO?
names(seleno_thingy) <- c("prot1", "prot2")

#Output
seleno_thingy
## $prot1
## [1] ">NP_060915.2 selenoprotein S isoform 1 [Homo sapiens]\nMERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQRQLDRAAAAV\nEPDVVVKRQEALAAARLKMQEELNAQVEKHKEKLKQLEEEKRRQKIEMWDSMQEGKSYKGNAKKPQEEDS\nPGPSTSSVLKRKSDRKPLRGGGYNPLSGEGGGACSWRPGRRGPSSGGUG\n\n"
## 
## $prot2
## [1] ">NP_001316384.1 glutathione peroxidase 1 isoform 5 [Homo sapiens]\nMCAARLAAAAAAAQSVYAFSARPLAGGEPVSLGSLRGKENAKNEEILNSLKYVRPGGGFEPNFMLFEKCE\nVNGAGAHPLFAFLREALPAPSDDATALMTDPKLITWSPVCRNDVAWNFEKFLVGPDGVPLRRYSRRFQTI\nDIEPDIEALLSQGPSCA\n\n"

Elements of the list are accessed like this

seleno_thingy[[1]]
## [1] ">NP_060915.2 selenoprotein S isoform 1 [Homo sapiens]\nMERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQRQLDRAAAAV\nEPDVVVKRQEALAAARLKMQEELNAQVEKHKEKLKQLEEEKRRQKIEMWDSMQEGKSYKGNAKKPQEEDS\nPGPSTSSVLKRKSDRKPLRGGGYNPLSGEGGGACSWRPGRRGPSSGGUG\n\n"

I’ll clean them with fasta_cleaner()

# first, make a copy of the list for storing the clean data
## I'm just going to copy over the old data
seleno_thingy_clean <- seleno_thingy


# HOW TO MAKE THIS MORE COMPACT?
for(i in 1:length(seleno_thingy_clean)){
   clean_fasta_temp <- compbio4all::fasta_cleaner(seleno_thingy[[i]],
                                                       parse = T)
  
  seleno_thingy_clean[[i]] <- clean_fasta_temp
}

Now the data looks like this THE FASTA FILES ARE STORED AS CHARACTERS

seleno_thingy_clean
## $prot1
##   [1] "M" "E" "R" "Q" "E" "E" "S" "L" "S" "A" "R" "P" "A" "L" "E" "T" "E" "G"
##  [19] "L" "R" "F" "L" "H" "T" "T" "V" "G" "S" "L" "L" "A" "T" "Y" "G" "W" "Y"
##  [37] "I" "V" "F" "S" "C" "I" "L" "L" "Y" "V" "V" "F" "Q" "K" "L" "S" "A" "R"
##  [55] "L" "R" "A" "L" "R" "Q" "R" "Q" "L" "D" "R" "A" "A" "A" "A" "V" "E" "P"
##  [73] "D" "V" "V" "V" "K" "R" "Q" "E" "A" "L" "A" "A" "A" "R" "L" "K" "M" "Q"
##  [91] "E" "E" "L" "N" "A" "Q" "V" "E" "K" "H" "K" "E" "K" "L" "K" "Q" "L" "E"
## [109] "E" "E" "K" "R" "R" "Q" "K" "I" "E" "M" "W" "D" "S" "M" "Q" "E" "G" "K"
## [127] "S" "Y" "K" "G" "N" "A" "K" "K" "P" "Q" "E" "E" "D" "S" "P" "G" "P" "S"
## [145] "T" "S" "S" "V" "L" "K" "R" "K" "S" "D" "R" "K" "P" "L" "R" "G" "G" "G"
## [163] "Y" "N" "P" "L" "S" "G" "E" "G" "G" "G" "A" "C" "S" "W" "R" "P" "G" "R"
## [181] "R" "G" "P" "S" "S" "G" "G" "U" "G"
## 
## $prot2
##   [1] "M" "C" "A" "A" "R" "L" "A" "A" "A" "A" "A" "A" "A" "Q" "S" "V" "Y" "A"
##  [19] "F" "S" "A" "R" "P" "L" "A" "G" "G" "E" "P" "V" "S" "L" "G" "S" "L" "R"
##  [37] "G" "K" "E" "N" "A" "K" "N" "E" "E" "I" "L" "N" "S" "L" "K" "Y" "V" "R"
##  [55] "P" "G" "G" "G" "F" "E" "P" "N" "F" "M" "L" "F" "E" "K" "C" "E" "V" "N"
##  [73] "G" "A" "G" "A" "H" "P" "L" "F" "A" "F" "L" "R" "E" "A" "L" "P" "A" "P"
##  [91] "S" "D" "D" "A" "T" "A" "L" "M" "T" "D" "P" "K" "L" "I" "T" "W" "S" "P"
## [109] "V" "C" "R" "N" "D" "V" "A" "W" "N" "F" "E" "K" "F" "L" "V" "G" "P" "D"
## [127] "G" "V" "P" "L" "R" "R" "Y" "S" "R" "R" "F" "Q" "T" "I" "D" "I" "E" "P"
## [145] "D" "I" "E" "A" "L" "L" "S" "Q" "G" "P" "S" "C" "A"

EACH ELEMENT OF THE LIST IS A VECTOR OF CHARACTER DATA

class(seleno_thingy_clean[[1]])
## [1] "character"
is(seleno_thingy_clean[[1]])
##  [1] "character"               "vector"                 
##  [3] "data.frameRowLabels"     "SuperClassMethod"       
##  [5] "character_OR_connection" "character_OR_NULL"      
##  [7] "atomic"                  "EnumerationValue"       
##  [9] "vector_OR_Vector"        "vector_OR_factor"
is.vector(seleno_thingy_clean[[1]])
## [1] TRUE

Make an dotplot

For old-times sake we can make a dotplot.
Now for a dotplot

WE’LL TAKE EACH VECTOR IN THE LIST AND MAKE IT INTO A SEPARATE OBJECT

prot1_vector <- seleno_thingy_clean[[1]]
prot2_vector <- seleno_thingy_clean[[2]]

We can dotplot like this

seqinr::dotPlot(prot1_vector,
                prot1_vector)

DIRECTLY CALLING THE VECTORS FROM THE LIST IN THE DOTPLOT CALL

seqinr::dotPlot(seleno_thingy_clean[[1]],
                seleno_thingy_clean[[2]])

Pairwise alignment

dotPlot likes things in a single vector, but pairwiseAlignment like a single string of characters, so as always we have to process the data.

TURNING THE VECTOR OF SEPARATE ELEMENTS OF CHARACTERS AND MAKING IT A SINGLE ELEMENT WITH ALL THE CHARACTERS. "" MEANS TO CONDENSE WITH NO SPACES

prot1_str <- paste(seleno_thingy_clean[[1]],sep = "", collapse = "")
prot2_str <- paste(seleno_thingy_clean[[2]],sep = "", collapse = "")

So now things look like this

A VECTOR OF LENGTH 1 WITH THE ENTIRE SEQUENCE IN A SINGLE ELEMENT OF THE VECTOR

prot1_str
## [1] "MERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQRQLDRAAAAVEPDVVVKRQEALAAARLKMQEELNAQVEKHKEKLKQLEEEKRRQKIEMWDSMQEGKSYKGNAKKPQEEDSPGPSTSSVLKRKSDRKPLRGGGYNPLSGEGGGACSWRPGRRGPSSGGUG"

Protein alignments need a amino acid transition matrix, and we need to use data() to bring those up into active memory (VERY IMPORTANT STEP!)

data(BLOSUM50)

The alignment

align_out <- Biostrings::pairwiseAlignment(pattern = prot1_str, 
                              subject = prot2_str, 
                              type = "global",
                              gapOpening = -9.5,
                              gapExtension = -0.5)

RAW OUTPUT, GIVES THE SCORE FOR ALIGNMENT

align_out
## Global PairwiseAlignmentsSingleSubject (1 of 1)
## pattern: MERQEESLSARPALETEGLRFLHTTVGSLLATYG...-----------------ACSWRPGRRGPSSGGUG
## subject: M---------------------------------...IDIEPDIEALLSQGPSCA----------------
## score: -160.2561

FULL ALIGNMENT - SHOULD HAVE A LOT OF GAPS

compbio4all::print_pairwise_alignment(align_out)
## [1] "MERQEESLSARPALETEGLRFLHTTVGSLLATYGWYIVFSCILLYVVFQKLSARLRALRQ 60"
## [1] "M---------------------------------------C----------AARL----- 6"
## [1] " "
## [1] "RQLDRAAAAVEPDVVVKRQEALAAA--------RLKMQEELNAQVEKHKEKLKQLEEEKR 112"
## [1] "-----AAAA-------------AAAQSVYAFSAR-------------------------- 22"
## [1] " "
## [1] "RQKIEMWDSMQEGKSYKGNAKKPQEEDSPGPSTSSVLKRKSDRKPLRGGGYNPLSGE--- 169"
## [1] "--------------------------------------------PLAGG-------EPVS 31"
## [1] " "
## [1] "------------------------GGG--------------------------------- 172"
## [1] "LGSLRGKENAKNEEILNSLKYVRPGGGFEPNFMLFEKCEVNGAGAHPLFAFLREALPAPS 91"
## [1] " "
## [1] "------------------------------------------------------------ 172"
## [1] "DDATALMTDPKLITWSPVCRNDVAWNFEKFLVGPDGVPLRRYSRRFQTIDIEPDIEALLS 151"
## [1] " "
## [1] "-----A 227"
## [1] "QGPSCA 211"
## [1] " "

These are two randomly chosen sequences, so the alignment should be pretty BAD

The score is negative, but on its own ITS HARD TO INTERPRET, EVEN GOOD ALIGNMENTS CAN BE NEGATIVE

score(align_out)
## [1] -160.2561

pid gives us A MORE INTUITIVE SENSE OF HOW THE 2 SEQUENCES MATCH

pid(align_out)
## [1] 7.189542

Of course, pid can be calculated several ways USING DIFFERENT DENOMINATORS. EACH TELLS US A DIFFERENT ASPECT OF SIMILARITY BETWEEN THE TWO SEQUENCES

pid(align_out,type = "PID1")
## [1] 7.189542
pid(align_out,type = "PID2")
## [1] 91.66667
pid(align_out,type = "PID3")
## [1] 14.01274
pid(align_out,type = "PID4")
## [1] 12.71676