Biomaterial Database

The PapG protein is the alpha-D-galactopyranosyl-(1----4)-beta-D-galactopyranose-binding adhesin of uropathogenic Escherichia coli. 1987

B Lund, and F Lindberg, and B I Marklund, and S Normark

Uropathogenic Escherichia coli adhere to uroepithelial cells by their digalactoside alpha-D-galactopyranosyl-(1----4)-beta-D-galactopyranose [alpha-D-Galp-(1----4)-beta-D-Galp or Gal alpha (1----4)Gal]-binding pili, which are composed of repeating identical subunits. The major subunit (PapA) of these pili is not required for binding, but the papF and papG gene products are essential for adhesion. Transcomplementation analysis between the pap gene cluster and a related gene cluster encoding a different binding specificity showed that PapG and not PapF is the Gal alpha (1----4)Gal-specific adhesin. Antibodies against PapG were obtained upon immunizing with whole Pap pili, showing that the adhesin is a pilus component. Antisera specific for different Pap proteins were used to demonstrate that a pilin protein, either PapA or PapE, together with both PapG and PapF, must be exposed on the cell surface to allow E. coli to bind. The DNA sequence of the papG gene is presented, and the deduced primary structure showed similarities both to the B-chain sequence of the digalactoside-binding Shigella toxin and to established amino acid sequences of pilins.

UI	MeSH Term	Description	Entries
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001422	Bacterial Adhesion	Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.	Adhesion, Bacterial,Adhesions, Bacterial,Bacterial Adhesions
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D018830	Adhesins, Escherichia coli	Thin, filamentous protein structures, including proteinaceous capsular antigens (fimbrial antigens), that mediate adhesion of E. coli to surfaces and play a role in pathogenesis. They have a high affinity for various epithelial cells.	Escherichia coli Adhesins,Adhesin, E coli,Adhesin, Escherichia coli,E coli Adhesin,Escherichia coli Adhesin