Protein Family Models

This HMM described a domain that is often repeated in pilins such as SpaA, and that often forms isopeptide bonds cross-linking amino acid side chains, giving the pilins added strength.

Date:

2024-10-16

Date:

2024-08-14

This model represents the conserved region of about 53 amino acids shared between regions, usually repeated, of proteins from a small number of phylogenetically diverse prokaryotes. The model overlaps significantly in coverage with DUF11 (PF01345). Examples of the domain occur within longer repeats in three of the five longest proteins of Bacillus anthracis, in a 131-residue repeat in a cell wall-anchored protein of Enterococcus faecalis, and a 120-residue repeat in Methanobacterium thermoautotrophicum. A similar region is found in some Chlamydial outer membrane proteins.

Date:

2021-07-15

Members of this family are pilin major subunits whose structure includes an LPXTG motif-containing signal (see TIGR01167) near the C-terminus, for processing by sortases. Most contain a recognizable D2-type fimbrial isopeptide formation domain (see TIGR04226), in which Lys-to-Asn isopeptide bond formation provides additional structural integrity to support adhesion despite shear. For proper members of this subfamily, lengths fall typically in the range of 460 to 640 amino acids in length. Many members of this family contribute to the virulence of certain Gram-positive pathogens, including SpaA, SpaD, and SpaH from Corynebacterium diphtheriae, and EbpB and EbpC from Enterococcus faecalis.

Date:

2020-10-26

This model describes the LPXTG motif-containing region found at the C-terminus of many surface proteins of Streptococcus and Streptomyces species. Cleavage between the Thr and Gly by sortase or a related enzyme leads to covalent anchoring at the new C-terminal Thr to the cell wall. Hits that do not lie at the C-terminus or are not found in Gram-positive bacteria are probably false-positive. A common feature of this proteins containing this domain appears to be a high proportion of charged and zwitterionic residues immediatedly upstream of the LPXTG motif. This model differs from other descriptions of the LPXTG region by including a portion of that upstream charged region.

Date:

2021-04-27