二穗短柄草BURP家族基因的鉴定与分析

Identification and Analysis of BURP Family Genes in Brachypodium distachyon

BURP是一类植物特有蛋白，在生长发育和逆境防御中起着重要作用。为给后续的基因克隆、表达和功能验证奠定基础，根据二穗短柄草的基因组和蛋白质序列，利用生物信息学手段对BURP基因家族成员进行鉴定、染色体定位、序列分析和系统发育研究。结果表明，二穗短柄草有12个Bu品P基因，位于1～4号染色体上，在5号染色体上未见分布；BURP基因的全长为621～3350bp，具0～3个内含子，编码区全长621～2316bp，编码206～771个氨基酸，推导蛋白的等电点为5．02～9．51；12个BURP基因编码的蛋白分为5组，分别定名为RD22、PG1β、BURP—V、BURP—VI和BURP—VII，没有usP和BNM2类型的BuRP蛋白；此外，根据4个半胱氨酸一组氨酸重复所闻隔的氨基酸数量，二穗短柄草的BURP蛋白结构域可用CH／R—X10-CH—X25—36-CH—X22—25-CH—X8-W／F表示。

BURPs are a group of plant-specific proteins which play important roles in development and stress defences. To lay the basis for future studies of gene isolation, expression and functional analysis, bioinformatic approaches were employed to identify BURP family numbers, chromosomal localization, sequence analysis as well as phylogenetic analysis using Brachypodium distachyon genome sequences and protein database. A total of 12 BURP genes were identified, which located on chromosomes 1-4. However, no distribution was observed on chromosome 5. The full genome sequences of BURP genes were 621 to 3 350 bp in length with 0-3 introns. The coding sequences were 621 to 2 316 bp encoding 206 to 771 amino acids. The isoelectrie points of deduced proteins ranged from 5.02 to 9.51. According to the results of phylogenetic analysis, the 12 BURPs were classified into five sub- families, designated as RD22, PG1β, BURP-V, BURP-VI and BURP-VII. However, USP and BNM2 types of BURPs were not included. Based on the numbers of amino acids separated by four cysteine-histidine repeats, B. distachyon BURP domains were described as CH/R-X10-CH-X25-36-CH- X22-25-CH-XS-W/F.