沼泽红假单胞菌Rhodopseudomonas palustris 2-8的亚硝酸盐还原酶基因克隆和序列分析

Cloning and sequence analysis of nitirite reductase gene from the Rodopseudomonas palustris strain 2-8

摘要:

沼泽红假单胞菌2-8具有亚硝酸盐还原能力, 根据不同类型亚硝酸盐还原酶保守序列设计引物, 通过PCR扩增的方法对2-8菌株的亚硝酸盐还原酶类型进行鉴定, 发现该菌株的亚硝酸盐还原酶为Cu型亚硝酸盐还原酶。从2-8菌株基因组中克隆出编码该Cu型亚硝酸盐还原酶的基因(nirK), 该基因由1 154个碱基对组成, 在GenBank数据库的登录号为GU332847, 与沼泽红假单胞菌Rhodopseudomonas palustris TIE和CGA009的nirK序列相似性为90%。互联网数据库及生物信息学分

Abstract:

The nitrite reductase type of Rhodopseudomonas palustris strain 2-8, a denitrifying bacteria, was identified by polymerase chain reaction (PCR) and bioinformatics analysis as Cu-containing nitrite reductase (CuNiR). The gene encoding Cu-containing nitrite reductase, nirK, has been cloned and sequenced. The nirK gene was 1 154 bases in length and has significant identity with the nirK sequences of Rhodopseudomonas palustris TIE and Rhodopseudomonas palustris CGA009, their identity were both 90%, and it has been deposited with the GenBank Data Libraries under accession number GU332847. Bioinformatics analysis showed it coded a protein consisting of 370 amino acids, this protein was a kind of Cu-containing dissimilatory nitrite reductase, and it was stable, pI 6.2, located in periplasmic or out of membrane, composed of alpha helix, extended strand, random coil and ambigous states. There were four 2Fe-2S ferredoxin-type iron-sulfur binding region signatures and one 4Fe-4S ferredoxin-type iron-sulfur binding region signature. Northern hybridization result showed this nirK gene presented as a single copy and has been transcripted in the cell of Rhodopseudomonas palustris 2-8.