Integrated Transcriptome and Proteome Studies Reveal the Underlying Mechanisms for Sterol Catabolism and Steroid Production in Mycobacterium neoaurum

Integrated
transcriptome and proteome studies were performed to
investigate sterol biotransformation in wild-type Mycobacterium
neoaurum ATCC 25795 (Mn) and the
mutant strains producing steroid intermediates. Transcriptome and
proteome studies indicated that several metabolic activities were
noticeably dynamic, including cholesterol degradation, central carbon
metabolism, cell envelope biosynthesis, glycerol metabolism, and transport.
Interestingly, a poor overall correlation between mRNA and translation
profiles was found, which might contribute to the metabolic adaptation
in cholesterol catabolism. A gene cluster covering 111 genes was discovered
to encode for cholesterol catabolism in Mn. Generally,
transcription and/or translation of the genes in KstR1 regulon was
upregulated, and the induction of genes in KstR2 regulon was not as
significant as that of KstR1 regulon. Several induced genes showing
potential roles for cholesterol catabolism were found. Further identification
of these genes and investigation of the correlation among key metabolic
activities could help for the development of efficient steroid-producing
strains.