C. Vargas et al., IDENTIFICATION OF SYMBIOSIS-SPECIFIC C-TYPE CYTOCHROMES AND A PUTATIVE OXIDASE IN BACTEROIDS OF RHIZOBIUM-LEGUMINOSARUM BIOVAR VICIAE, Microbiology, 142, 1996, pp. 41-46
Covalently bound haem proteins and cytochromes were analysed in Rhizob
ium leguminosarum biovar viciae free-living cells and nitrogen-fixing
bacteroids isolated from pea nodules. Increased levels of spectroscopi
cally detectable cytochrome c in bacteroids were correlated with the a
ppearance of two proteins of M(r) 30 000 and 28 000 that contained cov
alently bound haem. Conversely, bacteroids had undetectable levels of
a periplasmic cytochrome c of M(r) 14 000 that is normally present in
free-living bacteria. Difference spectra confirmed that the terminal o
xidases, cytochromes aa(3) and d(1) were absent, and photodissociation
spectra revealed novel components that may be due to a bacteroid term
inal oxidase.