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Novel flavohemoglobins of mycobacteria
Author(s) -
Gupta Sanjay,
Pawaria Sudesh,
Lu Changyuan,
Yeh SyunRu,
Dikshit Kanak L.
Publication year - 2011
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1002/iub.460
Subject(s) - biology , heme , reductase , biochemistry , gene , genetics , sequence alignment , phylogenetic tree , ferredoxin , peptide sequence , enzyme
Flavohemoglobins (flavoHbs) constitute a distinct class of chimeric hemoglobins in which a globin domain is coupled with a ferredoxin reductase such as FAD‐ and NADH‐binding modules. Structural features and active site of heme and reductase domains are highly conserved in various flavoHbs. A new class of flavoHbs, displaying crucial differences in functionally conserved regions of heme and reductase domains, have been identified in mycobacteria. Mining of microbial genome data indicated that the occurrence of such flavoHbs might be restricted to a small group of microbes unlike conventional flavoHbs that are widespread among prokaryotes and lower eukaryotes. One of the representative flavoHbs of this class, encoded by Rv0385 gene (MtbFHb) of Mycobacterium tuberculosi s, has been cloned, expressed, and characterized. The ferric and deoxy spectra of MtbFHb displayed a hexacoordinate state indicating that its distal site may be occupied by an intrinsic amino acid or an external ligand and it may not be involved in nitric oxide detoxification. Phylogenetic analysis revealed that mycobacterial flavoHbs constitute a separate cluster distinct from conventional flavoHbs and may have novel function(s). © 2011 IUBMB IUBMB Life, 63(5): 337–345, 2011