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

This domain is found in a wide variety of contexts, but mostly occurring in cell wall associated proteins. A lack of conserved catalytic residues suggests that it is a binding domain. From context, possible substrates are hyaluronate or fibronectin (personal obs: C Yeats). This is further evidenced by [1]. Possibly the exact substrate is N-acetyl glucosamine. Finding it in the same protein as Pfam:PF05089 further supports this proposal. It is found in the C-terminal part of Swiss:O82833, which is removed during maturation ([2]). Some of the proteins it is found in (e.g. Swiss:Q9RL69) are involved in methicillin resistance ([3]). The name FIVAR derives from Found In Various Architectures. [1]. 12438356. Identification of a fibronectin-binding protein from Staphylococcus epidermidis. Williams RJ, Henderson B, Sharp LJ, Nair SP;. Infect Immun 2002;70:6805-6810. [2]. 14759609. Posttranslational processing of polysaccharide lyase: maturation route for gellan lyase in Bacillus sp. GL1. Miyake O, Kobayashi E, Nankai H, Hashimoto W, Mikami B, Murata K;. Arch Biochem Biophys 2004;422:211-220. [3]. 10896508. Tn551-mediated insertional inactivation of the fmtB gene encoding a cell wall-associated protein abolishes methicillin resistance in Staphylococcus aureus. Komatsuzawa H, Ohta K, Sugai M, Fujiwara T, Glanzmann P, Berger-BachiB, Suginaka H;. J Antimicrob Chemother 2000;45:421-431. (from Pfam)

Date:

2024-10-16

The GA (protein G-related Albumin-binding) module is composed of three alpha helices [1]. This module is found in a range of bacterial cell surface proteins. The GA module from Swiss:Q51911 shows a strong affinity for albumin. [1]. 9086265. Solution structure of the albumin-binding GA module: a versatile bacterial protein domain. Johansson MU, de Chateau M, Wikstrom M, Forsen S, Drakenberg T, Bjorck L. J Mol Biol 1997;266:859-865. (from Pfam)

Date:

2024-10-16

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