A protein having similarity with methylmalonyl-CoA mutase is required for the assimilation of methanol and ethanol by Methylobacterium extorquens AM1.
A 4.0 kb region of Methylobacterium extorquens AM1 DNA which complements three mutants unable to convert acetyl-CoA to glyoxylate (and therefore defective in the assimilation of methanol and ethanol) has been isolated and sequenced. It contains two ORFs and the 3'-end of a third one. The mutations in all three mutants mapped within the first ORF, which was designated meaA; it encodes a protein having similarity with methylmalonyl-CoA mutase. However, methylmalonyl-CoA mutase was measured in extracts of one of the mutants and the specific activity was found to be similar to that in extracts of wild-type cells. Furthermore, although the predicted meaA gene product has the proposed cobalamin-binding site, it does not contain a highly conserved sequence (RIARNT) which is present in all known methylmalonyl-CoA mutases; meaA may therefore encode a novel vitamin-B12-dependent enzyme. The predicted polypeptide encoded by the second ORF did not have similarity with any known proteins. The partial ORF encoded a protein with similarity with the 3-oxoacyl-[acyl-carrier-protein] reductases; it was not essential for growth on methanol or ethanol.
Smith
Loraine M
LM
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.|School of Cell and Molecular Biology, NESCOT, Reigate Road, Epsom KT17 3DS, UK.
Meijer
Wim G
WG
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
Dijkhuizen
Lubbert
L
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
Goodwin
Pat M
PM
School of Cell and Molecular Biology, NESCOT, Reigate Road, Epsom KT17 3DS, UK.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D000431:Ethanol / Q000378:metabolism; D006088:Gram-Negative Aerobic Bacteria / Q000378:metabolism*; D000432:Methanol / Q000378:metabolism; D008765:Methylmalonyl-CoA Mutase / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D015183:Restriction Mapping; D016415:Sequence Alignment
D001426:Bacterial Proteins; D000431:Ethanol; D008765:Methylmalonyl-CoA Mutase; D000432:Methanol