Role of alpha -Methylacyl Coenzyme A Racemase in the Degradation of Methyl- Branched Alkanes by Mycobacterium sp. Strain P101

Sakai, Y; Takahashi, H; Wakasa, Y; Kotani, T; Yurimoto, H; Miyachi, N; Van Veldhoven, PP; Kato, N

HERO ID

4968840

Reference Type

Journal Article

Year

2004

Language

English

PMID

15489432

HERO ID 4968840
In Press No
Year 2004
Title Role of alpha -Methylacyl Coenzyme A Racemase in the Degradation of Methyl- Branched Alkanes by Mycobacterium sp. Strain P101
Authors Sakai, Y; Takahashi, H; Wakasa, Y; Kotani, T; Yurimoto, H; Miyachi, N; Van Veldhoven, PP; Kato, N
Journal Journal of Bacteriology
Volume 186
Issue 21 (Nov 1
Page Numbers 7214-7220
Abstract A new isolate, Mycobacterium sp. strain P101, is capable of growth on methyl-branched alkanes (pristane, phytane, and squalane). Among ca. 10,000 Tn5- derived mutants, we characterized 2 mutants defective in growth on pristane or n-hexadecane. A single copy of Tn5 was found to be inserted into the coding region of mcr ( alpha -methylacyl coenzyme A [ alpha -methylacyl-CoA] racemase gene) in mutant P1 and into the coding region of mls (malate synthase gene) in mutant H1. Mutant P1 could not grow on methyl-branched alkanes. The recombinant Mcr produced in Escherichia coli was confirmed to catalyze racemization of (R)-2- methylpentadecanoyl-CoA, with a specific activity of 0.21 mu mol . min super(-1) . mg of protein super(-1). Real-time quantitative reverse transcriptase PCR analyses indicated that mcr gene expression was enhanced by the methyl-branched alkanes pristane and squalane. Mutant P1 used (S)-2-methylbutyric acid for growth but did not use the racemic compound, and growth on n-hexadecane was not inhibited by pristane. These results suggested that the oxidation of the methyl-branched alkanoic acid is inhibited by the (R) isomer, although the (R) isomer was not toxic during growth on n-hexadecane. Based on these results, Mcr is suggested to play a critical role in beta-oxidation of methyl-branched alkanes in MYCOBACTERIUM: On the other hand, mutant H1 could not grow on n-hexadecane, but it partially retained the ability to grow on pristane. The reduced growth of mutant H1 on pristane suggests that propionyl-CoA is available for cell propagation through the 2-methyl citric acid cycle, since propionyl-CoA is produced through beta-oxidation of pristane.
Doi 10.1128/JB.186.21.7214-7220.2004
Pmid 15489432
Wosid WOS:000224575500018
Url https://www.scopus.com/inward/record.uri?eid=2-s2.0-6044230915&doi=10.1128%2fJB.186.21.7214-7220.2004&partnerID=40&md5=ba473a60da1ae8379733453c951b8dc4
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword Alkanes; Biodegradation; pristane; Racemization; Malate synthase; Isomers; Gene expression; Coenzyme A; Oxidation; RNA-directed DNA polymerase; Polymerase chain reaction; Tricarboxylic acid cycle; Propagation; Mycobacterium; Escherichia coli; 2004)
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