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

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.