Class IV polyhydroxyalkanoate (PHA) synthases and PHA-producing Bacillus

摘要: This review highlights the recent investigations of class IV polyhydroxyalkanoate (PHA) synthases, newest classification PHA synthases. Class synthases are prevalent in organisms Bacillus genus and composed a catalytic subunit PhaC (approximately 40 kDa), which has box sequence ([GS]-X-C-X-[GA]-G) at active site, second PhaR 20 kDa). The representative PHA-producing strains megaterium cereus; nucleotide phaC genetic organization biosynthesis gene locus somewhat different between these two strains. It is generally considered that favor short-chain-length monomers such as 3-hydroxybutyrate (C4) 3-hydroxyvalerate (C5) for polymerization, but can polymerize some unusual minor components. In Escherichia coli expressing PhaRC from B. cereus YB-4, biosynthesized undergoes synthase-catalyzed alcoholytic cleavage using endogenous exogenous alcohols. alcoholysis thought to be shared among this reaction useful not only regulation molecular weight also modification carboxy terminus. novel properties will open up possibility design new materials.