Protein Family Models

This putative domain is found at the N-terminus of a large number of bacterial proteins. Its adhesive function was described in Lactobacillus reuteri serine-rich repeat proteins [1]. Structure predictions show it is composed of a beta solenoid repeat related to Pectate lyase. [1]. 29507249. Structural basis for the role of serine-rich repeat proteins. from Lactobacillus reuteri in gut microbe-host interactions.. Sequeira S, Kavanaugh D, MacKenzie DA, Suligoj T, Walpole S,. Leclaire C, Gunning AP, Latousakis D, Willats WGT, Angulo J,. Dong C, Juge N;. Proc Natl Acad Sci U S A. 2018;115:E2706. (from Pfam)

Date:

2024-08-14

This domain of bacterial surface proteins, about 80 amino acids long and often repeated 15 times or more in a protein sequence, is named for early described proteins such as Rib and alpha, but found in proteins with a wide variety of architectures and from various lineages.

Date:

2024-08-14

Many surface proteins found in Streptococcus, Staphylococcus, and related lineages share apparently homologous signal sequences. A motif resembling [YF]SIRKxxxGxxS[VIA] appears at the start of the transmembrane domain. The GxxS motif appears perfectly conserved, suggesting a specific function and not just homology. There is a strong correlation between proteins carrying this region at the N-terminus and those carrying the Gram-positive anchor domain with the LPXTG sortase processing site at the C-terminus. (from Pfam)

Date:

2024-08-14

The [YF]SIRKxxxGxxS type of signal peptide appears at the start of many proteins of Streptococcus, Staphylococcus, and Enterococcus, but not in other lineages such as Bacillus. Recent work in Staphylococcus aureus has shown that septal secretion (targeting to the crosswall in dividing cells) of the YSIRK-containing staphylococcal protein A depends on SecA, SecDF, and the lipoteichoic acid synthase LtaS, all of which co-purify when the motif is modified to YSIRKxxxGxxL to block processing.

Date:

2019-12-09

Sequences in this family are tandem repeats of about 79 amino acids, present in up to 14 copies in a protein and highly identical, even at the DNA level, within each protein. Sequences with these repeats are found in the Rib and alpha surface antigens of group B Streptococcus, Esp of Enterococcus faecalis, and related proteins of Lactobacillus. The repeat lacks Cys residues. Most members of this protein family also have the cell wall anchor motif LPXTG shared by many staphyloccal and streptococcal surface antigens.

Date:

2021-07-14