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How Salmonella oxidises H 2 under aerobic conditions
Author(s) -
Parkin Alison,
Bowman Lisa,
Roessler Maxie M.,
Davies Rosalind A.,
Palmer Tracy,
Armstrong Fraser A.,
Sargent Frank
Publication year - 2012
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2011.07.044
Subject(s) - hydrogenase , salmonella enterica , salmonella , chemistry , escherichia coli , microbiology and biotechnology , bacteria , enzyme , electron donor , biochemistry , biology , gene , catalysis , genetics
Salmonella enterica serovar Typhimurium is a Gram negative bacterial pathogen and a common cause of food‐borne illness. Molecular hydrogen has been shown to be a key respiratory electron donor during infection and H 2 oxidation can be catalysed by three genetically‐distinct [NiFe] hydrogenases. Of these, hydrogenases‐1 (Hyd‐1) and Hyd‐2 have well‐characterised homologues in Escherichia coli . The third, designated Hyd‐5 here, is peculiar to Salmonella and is expressed under aerobic conditions. In this work, Salmonella was genetically modified to enable the isolation and characterisation of Hyd‐5. Electrochemical analysis established that Hyd‐5 is a H 2 ‐oxidising enzyme that functions in very low levels of H 2 and sustains this activity in high levels of O 2 . In addition, electron paramagnetic resonance spectroscopy of the Hyd‐5 isoenzyme reveals a complex paramagnetic FeS signal at high potentials which is comparable to that observed for other O 2 ‐tolerant respiratory [NiFe] hydrogenases. Taken altogether, Hyd‐5 can be classified as an O 2 ‐tolerant hydrogenase that confers upon Salmonella the ability to use H 2 as an electron donor in aerobic respiration.