Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 15916613Journal NLM ID: 8712028Publisher: Blackwell Publishing
Institutions: Department of Microbiology and Immunology, Emory University School of Medicine, 3105 Rollins Research Center, 1510 Clifton Road N.E., Atlanta, GA 30322, USA
The RNA-binding protein CsrA represses biofilm formation, while the non-coding RNAs CsrB and CsrC activate this process by sequestering CsrA. We now provide evidence that the pgaABCD transcript, required for the synthesis of the polysaccharide adhesin PGA (poly-β-1,6-N-acetyl-d-glucosamine) of Escherichia coli, is the key target of biofilm regulation by CsrA. csrA disruption causes an approximately threefold increase in PGA production and an approximately sevenfold increase in expression of a pgaA'-'lacZ translational fusion. A ∆csrB∆csrC mutant exhibits a modest decrease in pgaA'-'lacZ expression, while the response regulator UvrY, a transcriptional activator of csrB and csrC, stimulates this expression. Biofilm formation is not regulated by csrA, csrB or uvrY in a ∆pgaC mutant, which cannot synthesize PGA. Gel mobility shift and toeprint analyses demonstrate that CsrA binds cooperatively to pgaA mRNA and competes with 30S ribosome subunit for binding. CsrA destabilizes the pgaA transcript in vivo. RNA footprinting and boundary analyses identify six apparent CsrA binding sites in the pgaA mRNA leader, the most extensive arrangement of such sites in any mRNA examined to date. Substitution mutations in CsrA binding sites overlapping the Shine-Dalgarno sequence and initiation codon partially relieve repression by CsrA. These studies define the crucial mechanisms, though not the only means, by which the Csr system influences biofilm formation
synthesis, expression, Gene Expression Regulation, Bacterial, genetics, growth & development, metabolism, microbiology, polysaccharide, Research, Escherichia, Escherichia coli, immunology, Molecular Sequence Data, protein, regulation, response, mutant, polysaccharides, production, mechanism, medicine, sequence, mutation, formation, binding, binding site, site, repression, RNA, Base Sequence, adhesin, biofilms, U.S.Gov't, decrease, Biofilm, mobility, substitution, influence, shift, P.H.S., gel, target, mRNA, in vivo, initiation, Research Support, fusion, Adhesins, Binding Sites, Escherichia coli Proteins, regulator, Repressor Proteins, N.I.H., Extramural, RNA-Binding Proteins
Structure type: homopolymer
Location inside paper: p.1648
Trivial name: poly-β-1,6-GlcNAc (PGA), biofilm, poly-b-(1-6)-N-acetyl-D-glucosamine (PNAG), poly-β-N-acetyl-glucosamine (PNAG), PNAG, poly-N-acetylglucosamine, PNAG
Compound class: CPS, EPS, O-polysaccharide, glucan, polysaccharide
Contained glycoepitopes: IEDB_135813,IEDB_137340,IEDB_141807,IEDB_151531,IEDB_753248
Methods: genetic methods
Biological activity: adhesin
Biosynthesis and genetic data: genetic data, biosynthetic data
Comments, role: biofilm component
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GTC:G36952FI, GlycomeDB:
11210
Show glycosyltransferases
There is only one chemically distinct structure:
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