Effect of oxygen on levels of mRNA coding for reaction-centre and light-harvesting polypeptides of Rhodobacter sphaeroides.
The relative levels of mRNA for the reaction-centre L and M subunits, B875 (LH1) alpha and beta polypeptides and B800-850 (LH2) alpha and beta polypeptides, have been measured during pigment induction of Rhodobacter sphaeroides. Over the 6 h of the experiment, bacteriochlorophyll levels increased by at least 100-fold. No transcripts for photosynthetic components were detectable at the start of induction; after 2 h the levels of transcripts from the puf operon (encoding reaction-centre and B875 subunits) had reached the maximum; these transcripts were 2.7 and 0.5 kb respectively. The transcript for the puc operon (B800-850 complex) was estimated to be 0.55 kb and reached a maximum level after 6 h. These results are consistent with the proposal that, during the assembly of the photosynthetic apparatus, the synthesis of B875 reaction-centre aggregates precedes that of the major antenna, B800-850.
Hunter
C N
CN
Department of Pure and Applied Biology, Imperial College, London, U.K.
Ashby
M K
MK
Coomber
S A
SA
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000378:metabolism; D045342:Light-Harvesting Protein Complexes; D010100:Oxygen / Q000494:pharmacology*; D010455:Peptides / Q000235:genetics*; D045322:Photosynthetic Reaction Center Complex Proteins; D011548:Pseudomonadaceae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects* / Q000235:genetics; D013053:Spectrophotometry
D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D045342:Light-Harvesting Protein Complexes; D010455:Peptides; D045322:Photosynthetic Reaction Center Complex Proteins; D012333:RNA, Messenger; D010100:Oxygen