將一個(gè)或多個(gè)序列寫(xiě)入FASTA格式的文件中，包括核酸序列和氨基酸序列。在R語(yǔ)言中，需要seqinr package。
代碼如下：
write.fasta(sequences, names, file.out, open = "w", nbchar = 60, as.string = FALSE)
write.fasta() 參數(shù)：
| 參數(shù) | 功能 |
|---|---|
| sequences | DNA或蛋白質(zhì)序列（默認(rèn)為單個(gè)字符的載體形式）或此類序列的列表 |
| names | 序列的名稱 |
| file.out | 輸出文件的名稱 |
| open | 打開(kāi)輸出文件的模式，使用“w”寫(xiě)入新文件，使用“a”將序列追加在已存在文件的末尾 |
| nbchar | 每行的字符數(shù)（默認(rèn)值：60） |
| as.string | 默認(rèn)為FALSE。設(shè)置為TRUE時(shí)，序列采用字符串形式而不是單個(gè)字符的向量 |
write.fasta() 函數(shù)實(shí)例：
實(shí)例采用 Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv) 的relA蛋白，其序列如下：MTAQRSTTNPVLEPLVAVHREIYPKADLSILQRAYEVADQRHASQLRQSGDPYITHPLAVANILAELGMDTTTLVAALLHDTVEDTGYTLEALTEEFGEEVGHLVDGVTKLDRVVLGSAAEGETIRKMITAMARDPRVLVIKVADRLHNMRTMRFLPPEKQARKARETLEVIAPLAHRLGMASVKWELEDLSFAILHPKKYEEIVRLVAGRAPSRDTYLAKVRAEIVNTLTASKIKATVEGRPKHYWSIYQKMIVKGRDFDDIHDLVGVRILCDEIRDCYAAVGVVHSLWQPMAGRFKDYIAQPRYGVYQSLHTTVVGPEGKPLEVQIRTRDMHRTAEYGIAAHWRYKEAKGRNGVLHPHAAAEIDDMAWMRQLLDWQREAADPGEFLESLRYDLAVQEIFVFTPKGDVITLPTGSTPVDFAYAVHTEVGHRCIGARVNGRLVALERKLENGEVVEVFTSKAPNAGPSRDWQQFVVSPRAKTKIRQWFAKERREEALETGKDAMAREVRRGGLPLQRLVNGESMAAVARELHYADVSALYTAIGEGHVSAKHVVQRLLAELGGIDQAEEELAERSTPATMPRRPRSTDDVGVSVPGAPGVLTKLAKCCTPVPGDVIMGFVTRGGGVSVHRTDCTNAASLQQQAERIIEVLWAPSPSSVFLVAIQVEALDRHRLLSDVTRALADEKVNILSASVTTSGDRVAISRFTFEMGDPKHLGHLLNAVRNVEGVYDVYRVTSAA
將此序列命名為MTrelA，fasta文件命名為MTrelA.fasta
輸入代碼：
library(seqinr)
seq<-c('MTAQRSTTNPVLEPLVAVHREIYPKADLSILQRAYEVADQRHASQLRQSGDPYITHPLAVANILAELGMDTTTLVAALLHDTVEDTGYTLEALTEEFGEEVGHLVDGVTKLDRVVLGSAAEGETIRKMITAMARDPRVLVIKVADRLHNMRTMRFLPPEKQARKARETLEVIAPLAHRLGMASVKWELEDLSFAILHPKKYEEIVRLVAGRAPSRDTYLAKVRAEIVNTLTASKIKATVEGRPKHYWSIYQKMIVKGRDFDDIHDLVGVRILCDEIRDCYAAVGVVHSLWQPMAGRFKDYIAQPRYGVYQSLHTTVVGPEGKPLEVQIRTRDMHRTAEYGIAAHWRYKEAKGRNGVLHPHAAAEIDDMAWMRQLLDWQREAADPGEFLESLRYDLAVQEIFVFTPKGDVITLPTGSTPVDFAYAVHTEVGHRCIGARVNGRLVALERKLENGEVVEVFTSKAPNAGPSRDWQQFVVSPRAKTKIRQWFAKERREEALETGKDAMAREVRRGGLPLQRLVNGESMAAVARELHYADVSALYTAIGEGHVSAKHVVQRLLAELGGIDQAEEELAERSTPATMPRRPRSTDDVGVSVPGAPGVLTKLAKCCTPVPGDVIMGFVTRGGGVSVHRTDCTNAASLQQQAERIIEVLWAPSPSSVFLVAIQVEALDRHRLLSDVTRALADEKVNILSASVTTSGDRVAISRFTFEMGDPKHLGHLLNAVRNVEGVYDVYRVTSAA
')
SeqName<-c('MTrelA')
write.fasta(seq, names=SeqName, file='MTrelAseq1.fasta', open='w', nbchar=60,
as.string = FALSE)
輸出結(jié)果：
