title: Lipolytic enzymes in Myxococcus xanthus.
abstract: The genome of Myxococcus xanthus encodes lipolytic enzymes in three different families: patatin lipases, alpha/beta hydrolases, and GDSL lipases. One member of each family was characterized. The protein encoded by MXAN_3852 contains motifs characteristic of patatins. MXAN_5522 encodes a protein with the G-X-S-X-G motif characteristic of the lipase subfamily of alpha/beta hydrolases. MXAN_4569 encodes a member of the GDSL family of lipolytic enzymes. Strains with deletions of MXAN_5522 and MXAN_4569 undergo faster development and earlier myxospore formation than the wild-type strain. The MXAN_5522 mutation results in spore yields substantially higher than those seen for wild-type cells. Gene expression analysis using translational lacZ fusions indicates that while all three genes are expressed during development, only MXAN_5522 and MXAN_4569 are expressed during vegetative growth. The proteins encoded by these genes were overexpressed using a T7 RNA polymerase transcription (pET102/D-TOPO) system in Escherichia coli BL21 Star (DE3) cells. The substrate specificities of the purified enzymes were investigated using p-nitrophenyl esters with chain lengths from C(2) to C(16). These enzymes preferentially hydrolyzed esters of short-chain fatty acids, yielding the highest activity with p-nitrophenyl acetate.
authors.affiliation: Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Moraleda-Muñoz
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Shimkets
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D043182:Carboxylesterase / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006868:Hydrolysis; D008049:Lipase; D008066:Lipolysis; D008969:Molecular Sequence Data; D016941:Myxococcus xanthus / Q000201:enzymology* / Q000254:growth & development; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D011994:Recombinant Proteins; D043182:Carboxylesterase; D008049:Lipase