Vargas Macías, CarmenWu, GuanghuiDavies, Andrea E.Downie, John Allan2016-06-232016-06-231994Vargas, C., Wu, G., Davies, A.E. y Downie, J.A. (1994). Identification of a gene encoding a thioredoxin-like product necessary for cytochrome c biosynthesis and symbiotic nitrogen fixation in Rhizobium leguminosarum. Journal of Bacteriology, 176 (13), 4117-4123.0021-9193http://hdl.handle.net/11441/42692A Tn5-induced mutant of Rhizobium leguminosarum bv. viciae could not form nitrogen-fixing nodules on pea or vetch because of a lesion in electron transport to oxygen. The mutant lacked spectroscopically detectable cytochromes c and aa3. No proteins containing c-type cytochromes could be identified in the mutant by heme staining of proteins fractionated on polyacrylamide gels, indicating that the mutant was defective in maturation of all c-type cytochromes. The Tn5 mutation was determined to be located in a gene that was called cycY. The cycY gene product is homologous to the thioredoxin-like protein HelX involved in the assembly of c-type cytochromes in Rhodobacter capsulatus and to an open reading frame from a Bradyrhizobium japonicum gene cluster containing other genes involved in cytochrome c biogenesis. Our observations are consistent with CycY functioning as a thioredoxin that reduces cysteine residues in apocytochromes c before heme attachmentapplication/pdfengAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess