GroEL1: a dedicated chaperone involved in mycolic acid biosynthesis during biofilm formation in mycobacteria.
Mycobacteria are unusual in encoding two GroEL paralogs, GroEL1 and GroEL2. GroEL2 is essential--presumably providing the housekeeping chaperone functions--while groEL1 is nonessential, contains the attB site for phage Bxb1 integration, and encodes a putative chaperone with unusual structural features. Inactivation of the Mycobacterium smegmatis groEL1 gene by phage Bxb1 integration allows normal planktonic growth but prevents the formation of mature biofilms. GroEL1 modulates synthesis of mycolates--long-chain fatty acid components of the mycobacterial cell wall--specifically during biofilm formation and physically associates with KasA, a key component of the type II Fatty Acid Synthase involved in mycolic acid synthesis. Biofilm formation is associated with elevated synthesis of short-chain (C56-C68) fatty acids, and strains with altered mycolate profiles--including an InhA mutant resistant to the antituberculosis drug isoniazid and a strain overexpressing KasA--are defective in biofilm formation.
Ojha
Anil
A
Pittsburgh Bacteriophage Institute, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Anand
Mridula
M
Bhatt
Apoorva
A
Kremer
Laurent
L
Jacobs
William R
WR
Hatfull
Graham F
GF
D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms; D018834:Chaperonin 60 / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009160:Mycobacteriophages / Q000235:genetics / Q000378:metabolism; D020102:Mycobacterium smegmatis / Q000235:genetics / Q000502:physiology*; D009171:Mycolic Acids / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment
D001426:Bacterial Proteins; D018834:Chaperonin 60; D005227:Fatty Acids; D018832:Molecular Chaperones; D009171:Mycolic Acids; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase