Protein Family Models

Pair of presumed choline-binding repeats often found adjacent to Pfam:PF01473. (from Pfam)

Date:

2024-08-14

This is an N-terminal immunoglobulin (Ig)-like domain found in esterases such as EstA. Analysis of the EstA structure confirms that it is a member of the alpha/beta hydrolase family, with a conserved Ser-Asp-His catalytic triad. The Ig-like domain presumably plays a role in the multimerization of EstA into an unusual hexameric structure. Additionally, it may also participate in the catalysis of EstA by guiding the substrate to the active site [1]. [1]. 19013466. Crystal structure and biochemical properties of a novel thermostable esterase containing an immunoglobulin-like domain. Levisson M, Sun L, Hendriks S, Swinkels P, Akveld T, Bultema JB, Barendregt A, van den Heuvel RH, Dijkstra BW, van der Oost J, Kengen SW;. J Mol Biol. 2009;385:949-962. (from Pfam)

Date:

2024-10-16

This family of proteins include acetyl xylan esterases (AXE), feruloyl esterases (FAE), and poly(3-hydroxybutyrate) (PHB) depolymerases. (from Pfam)

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

These repeats are characterised by conserved aromatic residues and glycines are found in multiple tandem copies in a number of proteins. The CW repeat is 20 amino acid residues long. The exact domain boundaries may not be correct. It has been suggested that these repeats in Swiss:P15057 might be responsible for the specific recognition of choline-containing cell walls [1]. Similar but longer repeats are found in the glucosyltransferases and glucan-binding proteins of oral streptococci and shown to be involved in glucan binding [2] as well as in the related dextransucrases of Leuconostoc mesenteroides. Repeats also occur in toxins of Clostridium difficile and other clostridia, though the ligands are not always known. [1]. 3422470. Molecular evolution of lytic enzymes of Streptococcus pneumoniae and its bacteriophages. Garcia E, Garcia JL, Garcia P, Arraras A, Sanchez-Puelles JM, Lopez R;. Proc Natl Acad Sci U S A 1988;85:914-918. [2]. 14527392. Structural basis for selective recognition of pneumococcal cell wall by modular endolysin from phage Cp-1. Hermoso JA, Monterroso B, Albert A, Galan B, Ahrazem O, Garcia P, Martinez-Ripoll M, Garcia JL, Menendez M;. Structure (Camb) 2003;11:1239-1249. [3]. 7860591. Tracking the evolution of the bacterial choline-binding domain: molecular characterization of the Clostridium acetobutylicum NCIB 8052 cspA gene. Sanchez-Beato AR, Ronda C, Garcia JL;. J Bacteriol 1995;177:1098-1103. [4]. 1830357. A family of clostridial and streptococcal ligand-binding proteins with conserved C-terminal repeat sequences. Wren BW;. Mol Microbiol 1991;5:797-803. [5]. 2307516. Sequence analysis of the gene. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

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