Protein Family Models

This domain is found in several cell surface proteins, such as extracellular matrix-binding protein ebh [1]. Some members are involved in antibiotic resistance (e.g Swiss:Q9RL69 and Swiss:Q9LCJ9) [2] and/or cellular adhesion (e.g. Swiss:Q931R6) [1]. In some proteins it is repeated more than fifteen times, being the most repeated domain in streptococci [3]. This is a predominantly alpha-helical domain that form a long, thin, fibre-like structure and it has been proposed to function as a stalk that helps the adhesive non-repeat region (NRR) of proteins protrude beyond the cell surface [4,5]. [1]. 12438342. Analysis of Ebh, a 1.1-megadalton cell wall-associated fibronectin-binding protein of Staphylococcus aureus. Clarke SR, Harris LG, Richards RG, Foster SJ;. Infect Immun 2002;70:6680-6687. [2]. 10332717. Mrp--a new auxiliary gene essential for optimal expression of methicillin resistance in Staphylococcus aureus. Wu SW, De Lencastre H;. Microb Drug Resist 1999;5:9-18. [3]. 22921469. Protein domain repetition is enriched in Streptococcal cell-surface proteins. Lin IH, Hsu MT, Chang CH;. Genomics. 2012;100:370-379. [4]. 33465168. A novel sialic acid-binding adhesin present in multiple species contributes to the pathogenesis of Infective endocarditis. Gaytan MO, Singh AK, Woodiga SA, Patel SA, An SS, Vera-Ponce de Leon A, McGrath S, Miller AR, Bush JM, van der Linden M, Magrini V, Wilson RK, Kitten T, King SJ;. PLoS Pathog. 2021;17:e1009222. [5]. 22977243. The extracellular protein factor Epf from Streptococcus pyogenes is a cell surface adhesin that binds to cells through an N-terminal domain containing a carbohydrate-bindin. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

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

FmtB (Factor affecting methicillin resistance in the presence of Triton X-100 B), as found in Staphylococcus aureus, is a minimally characterized LPXTG-anchored surface protein with 19 or so repeats of the DUF1542 (PF07564). Although named in a similar way, FmtB is unrelated to the teichoic acid D-Ala esterase FmtA, originally called Fmt. FmtB is often called a virulence factor.

Gene:

fmtB

Date:

2021-07-01

This domain, about 375 amino acids long on average, occurs only in Staphylococcus and Streptococcus. It occurs as a non-repetitive N-terminal domain of LPXTG-anchored surface proteins, including SasC, Mrp, and FmtB. This region in SasC was shown to be involved in cell aggregation and biofilm formation, which may explain the methicillin resistance seen for Mrp and FmtB.

Date:

2023-11-13

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:

2024-12-19