沼泽红假单胞菌Rhodopseudomonas palustris2-8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

作　　者：陈燕红[1] 程萍[1] 喻国辉[1] 潘丽晶[1] 

机构地区：[1]珠海市农业科学研究中心,广东珠海519075

出　　处：《微生物学通报》2011年第5期647-653,共7页Microbiology China

基　　金：广东省自然科学基金项目(No.07009702)

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析工具分析显示,该基因编码的由370个氨基酸残基组成的蛋白是铜型亚硝酸盐还原酶,属于一型多铜氧化酶,pI 6.2,是一种稳定蛋白,定位于膜外或周质;由α螺旋、延伸带、随机卷曲和模糊状态组成;有4个2Fe-2S氧化还原蛋白型铁硫结合结构域和一个4Fe-4S氧化还原蛋白型铁硫结合结构域。经Northern杂交分析显示nirK基因在沼泽红假单胞菌2-8中以单拷贝的形式存在并表达。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 se-quenced.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.

关 键 词：沼泽红假单胞菌 亚硝酸盐还原酶 Cu型亚硝酸盐还原酶 基因克隆 生物信息学 

分 类 号：Q93[生物学—微生物学]