Further evidence that two unique subunits are essential for expression of hydrogenase activity in Rhizobium japonicum.
AUTOR(ES)
Harker, A R
RESUMO
Eight strains of Rhizobium lacking hydrogenase uptake (Hup) activity and 17 transconjugant strains carrying the hup cosmids pHU1, pHU52, or pHU53 (G. R. Lambert, M. A. Cantrell, F. J. Hanus, S. A. Russell, K. R. Haddad, and H. J. Evans, Proc. Natl. Acad. Sci. USA, 82:3232-3236, 1985) were screened for Hup activity and the presence of immunologically detectable hydrogenase polypeptides. Crude extracts of these strains were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis with affinity-purified antibodies against the two subunits of purified hydrogenase (Mr 60,000 and 30,000). Derepressed transconjugants carrying the cosmid pHU52 were Hup+ and contained detectable levels of both hydrogenase subunit polypeptides. Non-derepressed strains, Hup- parent strains, and strains carrying cosmids other than pHU52 did not express Hup activity and contained no immunologically detectable protein. These data provide further evidence for the essential involvement of the smaller (Mr 30,000) subunit in the expression of hydrogenase activity in Rhizobium japonicum and suggest that the determinants for hydrogenase subunit synthesis are present on pHU52.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=214228Documentos Relacionados
- Regulation of hydrogenase in Rhizobium japonicum.
- Nickel is a component of hydrogenase in Rhizobium japonicum.
- Expression of hydrogenase activity in free-living Rhizobium japonicum
- Some properties of the nickel-containing hydrogenase of chemolithotrophically grown Rhizobium japonicum.
- Isolation of genes (nif/hup cosmids) involved in hydrogenase and nitrogenase activities in Rhizobium japonicum.
