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Characterization of a NarH‐interacting Protein that Regulates Anaerobic Growth of Pseudomonas aeruginosa
Author(s) -
Pulakat Lakshmi,
Raja Kumaraguru,
Gavini Nara
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.515.1
Subject(s) - pseudomonas aeruginosa , mutant , microbiology and biotechnology , operon , biology , azotobacter vinelandii , plasmid , nitrate reductase , gene , chemistry , biochemistry , nitrogenase , bacteria , genetics , enzyme , nitrogen fixation
The opportunistic pathogen Pseudomonas aeruginosa employs nitrate reductase encoded by narGHJI operon for anaerobic growth on nitrate rich airways of cystic fibrosis patients. PA3871, a gene of unknown function downstream to narGHJI codes for a protein with 29% homology to the NifM, a nif‐specific peptidyl‐prolyl cis/trasn isomerase (PPIase) essential for maturation of the NifH component of nitrogenase. We report clustering of a nifM‐like gene (PA3871) with narG‐H‐I‐J is conserved among 24 bacterial genomes and propose to rename PA3871 as narM due to its role in anaerobic growth of P. aeruginosa. When P. aeruginosa strains PA01, narH mutant PA40984 and narM mutant PA5734 were grown on solid and liquid glycerol nitrate medium under anaerobic conditions, narH mutant could not grow and narM mutant had ~50% retarded growth (P<0.05). When narM was subcloned into broad‐host range plasmid pBG1380 and introduced into Nif‐ nifM Azotobacter vinelandii BG98, narM could rescue the Nif+ phenotype. Thus, NarM could substitute NifM in maturation of the NifH. Protein‐protein interaction studies with BacterioMatch Two‐Hybrid system showed that NarM interacts with NifH and NarH (ƒÒ‐galactosidase Activity: 76.68+ 5.76, and 56.43+8.64 Miller units, respectively). Thus NarM is a NarH‐interacting anaerobic growth regulator of P. aeruginosa. (Funded by NSF MCB‐1041718 [LP] and NIH GM57636‐02[NG])