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Type I flavohemoglobin of mycobacterium smegmatis is a functional nitric oxide dioxygenase.

IR@IMTECH: CSIR-Institute of Microbial Technology, Chandigarh

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Title Type I flavohemoglobin of mycobacterium smegmatis is a functional nitric oxide dioxygenase.
 
Creator Thakur, Naveen
Gupta, Sanjay
Hade, Mangesh Dattu
Dikshit, Kanak L
 
Subject QR Microbiology
 
Description Two flavohemoglobins, type I and type II, displaying distinct structural features and cofactor binding sites coexist in Mycobacterium smegmatis; however, none of these flavohemeproteins are characterized so far. We have cloned and expressed type I flavohemoglobin (FHb1) of Mycobacterium smegmatis, encoded by MSMEG_1336, and characterized its spectral and functional properties. FHb1 exists as a monomer and displays spectral and functional characteristics similar to HMP of E. coli. Specific NO dioxygenase (NOD) activity of FHb1 was estimated to be 63.5 nmol heme(-1) sec(-1) , which was nearly eightfold higher than the HbN of M. tuberculosis and matched closely to the HMP of E. coli on the basis of cellular heme content. FHb1 preferred NADH for the NO dioxygenation and exhibited rapid reduction of flavin adenine dinucleotide and heme iron using NADH as electron donor. Level of FHb1 transcript increased significantly in M. smegmatis in the presence of acidified nitrite, and a nitric oxide-responsive transcriptional regulator of Rrf2 family exists together with the FHb1 under the same operon. These results suggested that FHb1 of M. smegmatis is a functional NOD and may be involved in the stress management of its host toward nitric oxide and nitrosative stress.
 
Publisher Wiley
 
Date 2014-06
 
Type Article
PeerReviewed
 
Relation http://onlinelibrary.wiley.com/doi/10.1002/iub.1275/abstract
http://crdd.osdd.net/open/1692/
 
Identifier Thakur, Naveen and Gupta, Sanjay and Hade, Mangesh Dattu and Dikshit, Kanak L (2014) Type I flavohemoglobin of mycobacterium smegmatis is a functional nitric oxide dioxygenase. IUBMB life, 66 (6). pp. 396-404. ISSN 1521-6551