Molecular and functional characterization of the Azorhizobium caulinodans ORS571 hydrogenase gene cluster.
In this work, we report the cloning and sequencing of the Azorhizobium caulinodans ORS571 hydrogenase gene cluster. Sequence analysis revealed the presence of 20 open reading frames hupTUVhypFhupSLCDFGHJK hypABhupRhypCDEhupE. The physical and genetic organization of A. caulinodans ORS571 hydrogenase system suggests a close relatedness to that of Rhodobacter capsulatus. In contrast to the latter species, a gene homologous to Rhizobium leguminosarum hupE was identified downstream of the hyp operon. A hupSL mutation drastically reduced the high levels of hydrogenase activity induced by the A. caulinodans ORS571 wild-type strain in symbiosis with Sesbania rostrata plants. However, no significant effects on dry weight and nitrogen content of S. rostrata plants inoculated with the hupSL mutant were observed in plant growth experiments.
Laboratorio de Microbiología, Departamento de Biotecnología-E.T.S. Ingenieros Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Cecilia
C
Baginsky
Jose-Manuel
JM
Palacios
Juan
J
Imperial
Tomás
T
Ruiz-Argüeso
Belén
B
Brito
D000595:Amino Acid Sequence; D020599:Azorhizobium caulinodans / Q000201:enzymology* / Q000235:genetics* / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D003001:Cloning, Molecular; D007887:Fabaceae / Q000378:metabolism / Q000382:microbiology; D005798:Genes, Bacterial; D006864:Hydrogenase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013559:Symbiosis
D001426:Bacterial Proteins; D006864:Hydrogenase