Protein Family Models

This is the catalytic domain of class A beta-lactamases [1]. It is closely related to Beta-lactamase, Pfam:PF00144, the serine beta-lactamase-like superfamily, which contains the distantly related Pfam:PF00905 and PF00768 D-alanyl-D-alanine carboxypeptidase. [1]. 19100272. Structure of PBP-A from Thermosynechococcus elongatus, a. penicillin-binding protein closely related to class A. beta-lactamases.. Urbach C, Evrard C, Pudzaitis V, Fastrez J, Soumillion P,. Declercq JP;. J Mol Biol. 2009;386:109-120. (from Pfam)

Date:

2024-08-14

In prokaryotes, membrane lipoproteins are synthesized with a precursor signal peptide, which is cleaved by a specific lipoprotein signal peptidase (signal peptidase II). The peptidase recognizes a conserved sequence and cuts upstream of a cysteine residue to which a glyceride-fatty acid lipid is attached [1]. Analysis of lipoprotein and non-lipoprotein signal peptides reveals that the two classes differ significantly only in the region close to the signal peptidase cleavage site. This region is apolar and has the consensus sequence LA(G,A) 1C in the lipoproteins, but is polar and has small, uncharged residues in positions - 3 and - 1 in the non-lipoproteins [2]. Specialised signal peptide containing a lipobox motif in the carboxyl region of the signal peptide carries a cysteine residue which is the invariable target for lipidation by lipoprotein diacylglyceryl transferase (Lgt). Lipidation at this residue serves to anchor the lipoprotein to the membrane. Lipidation has been considered to be a prerequisite for the action of lipoprotein signal peptidase (Lsp), which removes the signal peptide and leaves the cysteine of the lipobox as the new amino-terminal residue of the mature lipoprotein [3]. [1]. 2202727. Lipoproteins in bacteria.. Hayashi S, Wu HC;. J Bioenerg Biomembr. 1990;22:451-471.. [2]. 2664762. The structure of signal peptides from bacterial lipoproteins.. von Heijne G;. Protein Eng. 1989;2:531-534.. [3]. 18469106. Lipoprotein signal peptides are processed by Lsp and Eep of. Streptococcus uberis.. Denham EL, Ward PN, Leigh JA;. J Bacteriol. 2008;190:4641-4647. (from Pfam)

Date:

2024-08-14

This model finds serine hydrolases of many sorts, including class C beta-lactamases. Despite the name given by Pfam as a short-hand for this HMM, members proteins should be assumed to be something other than a beta-lactamase if RefSeq or PGAP uses this HMM for naming. True beta-lactamases are named by more specific HMMs.

Date:

2024-08-14

Gene:

bla

Date:

2024-03-19

Members of this family are BlaZ, a family of class A beta-lactamases found discovered in Staphylococcus aureus. Members of this family all share greater than 90% sequence identity. Within this tight group, immunotypic variants described as types A through D have been distinguished (see PMID:2783329). The allele called PC1, from Staphylococcus aureus strain PC1, is an example of a class A beta-lactamase BlaZ of type A. MecA systms for methicillin resistance include a blaZ gene. Note that a related beta-lactamase found in mecC-like systems may be referred to as BlaZ, but shares less than 70% identity and is not included in this family.

Gene:

blaZ

Date:

2024-03-19

class A beta-lactamase-related serine hydrolase, similar to beta lactamases which hydrolyze the amide bond of the beta-lactam ring via the formation of an acyl-enzyme covalent complex

Date:

2024-08-05

Gene:

bla

Date:

2022-02-22