PIP profiles of coronavirus spike proteins

#### General parameters for the analysis ####

## Use (or not) GIDAID sequences
## 
## A few genoes were not available in NCBI Genbank at the time of 
## this analysis, and had to be downloaded from GISAID. These sequences
##  can however not be redistributed, they should thus be downloaded 
##  manually to reproduce the full trees. Alternatively, useGISAID
##  can be set to FALSE, whcih will reproduce the analysis with almost 
##  all the sequences of the paper.
useGISAID <- TRUE


#### Define directories and files ####
dir <- list(main = '..')
dir$R <- file.path(dir$main, "scripts/R")

#### Create output directory for sequences ####
seqPrefix <- "spike_proteins"
dir$outseq <- file.path(
  dir$main, "results", seqPrefix, "PIP_profiles")
dir.create(dir$outseq, showWarnings = FALSE, recursive = TRUE)
# list.files(dir$outseq)

## Instantiate a list for output files
outfiles <- vector()

## Input files
infiles <- list()

#### Sequence collection ####

## Supported: 
collections <- c(
  "around-CoV-2", 
  "selected",
  "around-CoV-2-plus-GISAID", 
  "selected-plus-GISAID"
  )

## Selected collection
# collection <- "around-CoV-2" # 14 strains
# collection <- "all" # 16 strains
# collection <- "selected" # ~60 strains
# collection <- "around-CoV-2-plus-GISAID" # 16 strains
collection <- "selected-plus-GISAID" # ~40 strains
# collection <- "all-plus-GISAID" # ~60 strains

## Use a collection-specific path for the figures
knitr::opts_chunk$set(
  fig.path = paste0('figures/spike-protein_PIP_', collection, '/', collection, "_"))


## Genome dir and files
if (length(grep(pattern = "GISAID", x = collection)) > 0) {
  useGISAID <- TRUE
  dir$sequences <- file.path(dir$main, "data", "GISAID_genomes")
} else {
  dir$sequences <- file.path(dir$main, "data", "genomes")
}

seqPrefix <- paste0("spike_proteins_", collection)

infiles$sequences <- file.path(dir$sequences, paste0(seqPrefix,".fasta"))

## Sequence sequences
if (!file.exists(infiles$sequences)) {
  stop("¨Protein sequence file is missing", "\n", infiles$sequences)
}


## Load custom functions
source(file.path(dir$R, "align_n_to_one.R"))
source(file.path(dir$R, "plot_pip_profiles.R"))


## Query patterns for SARS-CoV-2
queryPatterns <- list()
queryPatterns[["HuCoV2_WH01_2019"]] <- c(
  "PnGX-P1E_2017", 
  "PnGu1_2019",
  "BtRaTG13_2013_Yunnan", 
  "BtZC45",
  "BtZXC21",
  "HuSARS-Frankfurt-1_2003",
  "CmMERS",
  "HuMERS_172-06_2015"
)

queryPatterns[["PnGu1_2019"]] <- c(
  "HuCoV2_WH01_2019",
  "PnGX-P1E_2017",
  "BtRaTG13_2013_Yunnan"
)

queryPatterns[["BtRaTG13_2013_Yunnan"]] <- c(
  "HuCoV2_WH01_2019",
  "PnGX-P1E_2017",
  "PnGu1_2019"
)

queryPatterns[["HuSARS-Frankfurt-1_2003"]] <- c(
  "CvSZ3",
  "BtRs4874",
  "BtWIV16_2013",
  "BtRs4231",
  "BtRs7327",
  "BtRsSHC014",
  "Btrec-SARSp_2008",
  "PnGX-P1E_2017",
  "HuCoV2_WH01_2019",
  "BtRaTG13_2013_Yunnan", 
  "BtZC45",
  "BtZXC21",
  "CmMERS",
  "HuMERS_172-06_2015"
)

#### Add GISAID IDs to the query pattern ####
## Note that GISAID sequences are be submitted to the github repo because they cannot be redistributed
if (useGISAID) {
  for (ref in names(queryPatterns))
  queryPatterns[[ref]] <- append(queryPatterns[[ref]], 
                          c("BtYu-RmYN02_2019",
                            "PnGu1_2019"
                          ))
}

# message("\tReference strain: ", refPattern)
message("\tQuery patterns")
for (ref in names(queryPatterns)) {
  queryPatterns[[ref]] <- unique(queryPatterns[[ref]])
  message("\t", ref, "\t\t", length(queryPatterns[[ref]]),
          "\t", paste(collapse = ", ", queryPatterns[[ref]]))
}

#### Load sequences ####
sequences <- readAAStringSet(filepath = infiles$sequences, format = "fasta")

## Shorten sequence names by suppressing the fasta comment (after the space)
names(sequences) <- sub(pattern = " .*", replacement = "", x = names(sequences), perl = TRUE)

sequencesNames <- names(sequences)
nbsequences <- length(sequencesNames)
message("Loaded ", nbsequences, " sequences from file ", infiles$sequences)
# View(sequences)

#### Define reference and query sequences ####
refSequenceNames <- vector()
for (ref in names(queryPatterns)) {
  refSequenceNames[ref] <- unique(
    grep(pattern = ref, x = names(sequences), 
         ignore.case = TRUE, value = TRUE))
    if (is.null(refSequenceNames[ref])) {
    stop("Could not identify reference sequences with pattern ", ref)
  }
}

## Query sequences
# querySequenceNames <- list()
# for (ref in names(queryPatterns)) {
# #  message("Identifying query sequences for reference: ", ref)
#   queryRegExp <- paste0("(", paste(collapse = ")|(", queryPatterns[[ref]]), ")")
#   querySequenceNames[[ref]] <- grep(pattern = queryRegExp, 
#                              x = sequencesNames, 
#                              ignore.case = TRUE, value = TRUE)
#   nbquerySeq <- length(querySequenceNames[[ref]])
#   
#   if (nbquerySeq == 0) {
#     stop("Could not identify any query sequences with query pattern\n", queryRegExp)
#   }
#   
#   if (length(unlist(queryPatterns[ref[]])) != length(querySequenceNames[[ref]])) {
#     foundPatterns <- grep(pattern = queryRegExp, x = querySequenceNames[[ref]], value = TRUE)
#     missingPatterns <- setdiff(foundPatterns, queryPatterns[[ref]])
#     message("\t", 
#             length(missingPatterns), " Missing sequences: ", 
#             paste(collapse = ", ", missingPatterns))
#   }
#   
#   message("\tFound ", 
#           "\t", length(querySequenceNames[[ref]]), 
#           " queries for\t", ref)
# 
#   ## Compute some statistics about sequences sizes
#   sequencestat <- data.frame(
#     row.names = c(ref, querySequenceNames[[ref]]),
#     status = c("Reference", 
#                rep("Query", length.out = length(querySequenceNames[[ref]])))
#   )
#   
#   g <- 1
#   for (g in c(ref, querySequenceNames[[ref]])) {
#     sequencestat[g, "length"] <- length(sequences[[g]])
#   }
#   kable(sequencestat, caption = paste0("Query sequences for reference ", ref))
# }

Strain collection: selected-plus-GISAID

The collection selected-plus-GISAID contains 38 virus sequences sequences.

## Report the number of strains
strainNames <- names(sequences)
nbStrains <- length(strainNames)
message("\tLoaded ", nbStrains, " sequences from file ", infiles$sequences)
# View(genomes)

#### Compute sequence sizes ####
strainStats <- data.frame(
  n = 1:length(sequences),
  row.names = names(sequences),
  status = rep("Query", length.out = length(strainNames))
)
strainStats[,"status"] <- as.vector(strainStats[,"status"])
strainStats[refSequenceNames,"status"] <- "Reference"
g <- 1
for (g in strainNames) {
  strainStats[g, "length"] <- length(sequences[[g]])
}

#### Define the color associated to each sequence ####

## Color palette per species
speciesPalette <- list(
  Human = "#880000",
  Bat = "#888888",
  Pangolin = "#448800",
  Camel = "#BB8800",
  Pig = "#FFBBBB",
  Civet = "#00BBFF"
)

## Species prefix in the tip labels
speciesPrefix <- c("Hu" = "Human",
                   "Bt" = "Bat",
                   "Pn" = "Pangolin",
                   "Cm" = "Camel",
                   "Pi" = "Pig",
                   "Cv" = "Civet")

## Strain-specific colors
strainColor <- c(
  "HuCoV2_WH01_2019" = "red",
  "HuSARS-Frankfurt-1_2003" = "#0044BB",
  "BtRs4874" = "#BB00BB",
  "PnGu1_2019" = "#00BB00",
  "BtRaTG13_" = "#FF6600",
  "BtYu-RmYN" = "#FFBB22",
  "BtZXC21" = "black", 
  "BtZC45" = "black")

## Identify species per tip
for (prefix in names(speciesPrefix)) {
  strainStats[grep(pattern = paste0("^", prefix), x = row.names(strainStats), perl = TRUE), "species"] <- speciesPrefix[prefix]
  
}

## Assign acolor to each species
strainStats$color <- "grey" # default
strainStats$color <- speciesPalette[as.vector(strainStats$species)]

for (strain in names(strainColor)) {
  strainStats[grep(pattern = paste0("^", strain), 
                  x = row.names(strainStats), perl = TRUE), "color"] <- strainColor[strain]
  
}


## Assign specific color to some nodes

## Define a color for each strain
strainColors <- (unlist(strainStats$color))
names(strainColors) <- row.names(strainStats)

N-to-1 full sequence alignments

We perform a pairwise lignment between each sequences query and the reference sequences (HuCoV2_WH01_2019).

sequencesNto1 <- list()
refSequenceName <- "HuCoV2_WH01_2019"
for (refSequenceName in refSequenceNames) {
  ## Define output file for sequences alignments
  outfile <- file.path(
    dir$outseq, paste0("one-to-n_alignments_ref_", refSequenceName))
  outfiles[paste0(refSequenceName, " alignments")] <- outfile
  
  ## Get sequences for reference and query sequences
  refSequence <- sequences[refSequenceName]
  # querySeq <- sequences[querySequenceNames[[refSequenceName]]]
  
  message("\tAligning ", length(sequences), " sequences",
          " to reference\t", refSequenceName)

  sequencesNto1[[refSequenceName]] <- alignNtoOne(
    refSequence = refSequence,  
    querySequences = sequences, 
#    querySequences = querySeq, 
    sortByPIP = TRUE,
    #  querySequences = sequences, 
    outfile = outfile)
  
}

refSequenceName <- "HuCoV2_WH01_2019"

for (refSequenceName in refSequenceNames) {
  cat(sep = "", "\n## Spike proteins: ", collection, " vs reference ", refSequenceName)
  
  knitr::opts_chunk$set(
    fig.path = paste0('figures/spike-protein_PIP/', collection, '_vs_', refSequenceName))

  kable(sequencesNto1[[refSequenceName]]$stats[order(sequencesNto1[[refSequenceName]]$stats$score, decreasing = TRUE), ], 
        caption = "N-to-one alignment of full sequences")
  
  
  ## PIP profile of full sequences N-to-1 alignments
   if (length(grep(pattern = "around-CoV-2", x = collection))) {
     minPIP <- 30
     legendCex <- 1
     legendCorner <- "bottomright"
     legendMargin <- 0
   } else {
     minPIP <- 0
     legendCex <- 0.65
     legendCorner <- "topright"
     legendMargin <- 0.25
   }
   
  plotPIPprofiles(
    alignments = sequencesNto1[[refSequenceName]]$alignments, 
    windowSize = 100, 
    main = paste0("Spike protein: collection ", collection, "\nvs strain ", refSequenceName),
    colors = strainColors,
    legendMargin = legendMargin, 
    legendCorner = legendCorner, 
    lwd = 1,
    legendCex = legendCex, 
    ylim = c(minPIP,100))
  # legendMargin = 0.25, 
  # legendCorner = "topright", lwd = 1,
  # legendCex = 0.5, ylim = c(30, 100))
}

## Spike proteins: selected-plus-GISAID vs reference HuCoV2_WH01_2019

Percent Identical Positions (PIP) profiles of spike protein sequences.

## Spike proteins: selected-plus-GISAID vs reference PnGu1_2019

Percent Identical Positions (PIP) profiles of spike protein sequences.

## Spike proteins: selected-plus-GISAID vs reference BtRaTG13_2013_Yunnan

Percent Identical Positions (PIP) profiles of spike protein sequences.

## Spike proteins: selected-plus-GISAID vs reference HuSARS-Frankfurt-1_2003

Percent Identical Positions (PIP) profiles of spike protein sequences.

Output files

kable(t(as.data.frame(dir)), col.names = "Dir", caption = "Directories")

Directories
	Dir
main	..
R	../scripts/R
outseq	../results/spike_proteins/PIP_profiles
sequences	../data/GISAID_genomes

kable(outfiles, col.names = "File", caption = "Output files")

Output files
	File
HuCoV2_WH01_2019 alignments	../results/spike_proteins/PIP_profiles/one-to-n_alignments_ref_HuCoV2_WH01_2019
PnGu1_2019 alignments	../results/spike_proteins/PIP_profiles/one-to-n_alignments_ref_PnGu1_2019
BtRaTG13_2013_Yunnan alignments	../results/spike_proteins/PIP_profiles/one-to-n_alignments_ref_BtRaTG13_2013_Yunnan
HuSARS-Frankfurt-1_2003 alignments	../results/spike_proteins/PIP_profiles/one-to-n_alignments_ref_HuSARS-Frankfurt-1_2003

Session info

sessionInfo()

R version 3.6.1 (2019-07-05)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS Mojave 10.14.6

Matrix products: default
BLAS:   /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRblas.0.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats4    parallel  stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] Biostrings_2.52.0   XVector_0.24.0      IRanges_2.18.3      S4Vectors_0.22.1    BiocGenerics_0.30.0 knitr_1.28         

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.4          digest_0.6.25       magrittr_1.5        evaluate_0.14       highr_0.8           zlibbioc_1.30.0     rlang_0.4.5         stringi_1.4.6       rmarkdown_2.1       tools_3.6.1         stringr_1.4.0       xfun_0.12           yaml_2.2.1          compiler_3.6.1     
[15] BiocManager_1.30.10 htmltools_0.4.0

PIP profiles of coronavirus spike proteins - protein and RNA sequences

Jacques van Helden

2020-05-24

Strain collection: selected-plus-GISAID

N-to-1 full sequence alignments

Output files

Session info