Open AccessRhizobium leguminosarum bv. viciae hypA gene is specifically expressed in pea ( Pisum sativum ) bacteroids and required for hydrogenase activity and processing
Author(s) -
Hernando Yolanda,
Palacios Jose,
Imperial Juan,
RuizArgüeso Tomás
Publication year - 1998
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1998.tb13332.x
Subject(s) - hydrogenase , rhizobium leguminosarum , biology , pisum , gene , mutant , nitrogenase , plasmid , protein subunit , biochemistry , enzyme , genetics , rhizobiaceae , bacteria , symbiosis , nitrogen fixation
Rhizobium leguminosarum bv. viciae strain UPM791 induces in symbiosis with peas the synthesis of a nickel‐containing hydrogenase which recycles the hydrogen evolved by nitrogenase. The genes required for synthesis of this hydrogenase, hupSLCDEFGHIJKhypABFCDEX , are clustered in the symbiotic plasmid. Analysis of a hypA ‐deficient mutant showed that HypA is essential for symbiotic hydrogenase activity and required for correct processing of the hydrogenase large subunit. Unlike other microoxically induced hyp genes, the hypA gene was only expressed in pea bacteroids from its own promoter. The hypA mRNA 5′ end was mapped 109 bp upstream of the translational start codon. This distinct pattern of expression suggests a different role for HypA and the remaining Hyp proteins in hydrogenase synthesis.