Putative peptidoglycan binding domain | |||||||||||
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Identifiers | |||||||||||
Symbol | PG_binding_1 | ||||||||||
Pfam | PF01471 | ||||||||||
Pfam clan | CL0244 | ||||||||||
InterPro | IPR002477 | ||||||||||
SCOP2 | 1lbu / SCOPe / SUPFAM | ||||||||||
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Peptidoglycan binding domains have a general peptidoglycan binding function and a common core structure consisting of a closed, three-helical bundle with a left-handed twist. It is found at the N or C terminus of a variety of enzymes involved in bacterial cell wall degradation. [2] [3] [4] Examples are:
Many of the proteins having this domain are as yet uncharacterised. However, some are known to belong to MEROPS peptidase family M15 (clan MD), subfamily M15A metallopeptidases. A number of the proteins belonging to subfamily M15A are non-peptidase homologues as they either have been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for the catalytic activity.
Eukaryotic enzymes can contain structurally similar PGBD-like domains. Matrix metalloproteinases (MMP), which catalyse extracellular matrix degradation, have N-terminal domains that resemble PGBD. Examples are gelatinase A (MMP-2), which degrades type IV collagen, [6] stromelysin-1 (MMP-3), which plays a role in arthritis and tumour invasion, [7] [8] and gelatinase B (MMP-9) secreted by neutrophils as part of the innate immune defence mechanism. [9] Several MMPs are implicated in cancer progression, since degradation of the extracellular matrix is an essential step in the cascade of metastasis. [10]
Humans genes encoding proteins containing this domain include:
Autolysins are endogenous lytic enzymes that break down the peptidoglycan components of biological cells which enables the separation of daughter cells following cell division. They are involved in cell growth, cell wall metabolism, cell division and separation, as well as peptidoglycan turnover and have similar functions to lysozymes.
Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are metalloproteinases that are calcium-dependent zinc-containing endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs belong to a larger family of proteases known as the metzincin superfamily.
DD-Transpeptidase is a bacterial enzyme that catalyzes the transfer of the R-L-αα-D-alanyl moiety of R-L-αα-D-alanyl-D-alanine carbonyl donors to the γ-OH of their active-site serine and from this to a final acceptor. It is involved in bacterial cell wall biosynthesis, namely, the transpeptidation that crosslinks the peptide side chains of peptidoglycan strands.
Gelatinases are enzymes capable of degrading gelatin through hydrolysis, playing a major role in degradation of extracellular matrix and tissue remodeling. Gelatinases are a type of matrix metalloproteinase (MMP), a family of enzymes that depend on zinc as a cofactor and can break down parts of the extracellular matrix. MMPs have multiple subgroups, including gelatinase A and gelatinase B. Gelatinases are assigned a variety of Enzyme Commission numbers: gelatinase A uses 3.4.24.24, and gelatinase B uses 3.4.24.35, in which the first three numbers are same. The first digit, 3, is the class. Class 3 enzymes are hydrolases, enzymes that catalyze hydrolysis reactions, that is, they cleave bonds in presence of water. The next digit represents sub-class 4, or proteases, which are enzymes who hydrolyze peptide bonds in proteins. The next number is the sub-subclass of 24, which consists of metalloendopeptidases which contain metal ions in their active sites, in this case zinc, which help in cleaving peptide bonds. The last part of the EC number is the serial number, identifying specific enzymes within a sub-subclass. 24 represents gelatinase A, which is a metalloproteinase that breaks down gelatin and collagen, while 35 represents gelatinase B, which hydrolyzes peptide bonds.
Lysins, also known as endolysins or murein hydrolases, are hydrolytic enzymes produced by bacteriophages in order to cleave the host's cell wall during the final stage of the lytic cycle. Lysins are highly evolved enzymes that are able to target one of the five bonds in peptidoglycan (murein), the main component of bacterial cell walls, which allows the release of progeny virions from the lysed cell. Cell-wall-containing Archaea are also lysed by specialized pseudomurein-cleaving lysins, while most archaeal viruses employ alternative mechanisms. Similarly, not all bacteriophages synthesize lysins: some small single-stranded DNA and RNA phages produce membrane proteins that activate the host's autolytic mechanisms such as autolysins.
Matrix metalloproteinase-9 (MMP-9), also known as 92 kDa type IV collagenase, 92 kDa gelatinase or gelatinase B (GELB), is a matrixin, a class of enzymes that belong to the zinc-metalloproteinases family involved in the degradation of the extracellular matrix. In humans the MMP9 gene encodes for a signal peptide, a propeptide, a catalytic domain with inserted three repeats of fibronectin type II domain followed by a C-terminal hemopexin-like domain.
72 kDa type IV collagenase also known as matrix metalloproteinase-2 (MMP-2) and gelatinase A is an enzyme that in humans is encoded by the MMP2 gene. The MMP2 gene is located on chromosome 16 at position 12.2.
Tissue inhibitor of metalloproteinases 2 (TIMP2) is a gene and a corresponding protein. The gene is a member of the TIMP gene family. The protein is thought to be a metastasis suppressor.
Stromelysin-2 also known as matrix metalloproteinase-10 (MMP-10) or transin-2 is an enzyme that in humans is encoded by the MMP10 gene.
In enzymology, a N-acetylmuramoyl-L-alanine amidase is an enzyme that catalyzes a chemical reaction that cleaves the link between N-acetylmuramoyl residues and L-amino acid residues in certain cell-wall glycopeptides.
Collagenase 3 is an enzyme that in humans is encoded by the MMP13 gene. It is a member of the matrix metalloproteinase (MMP) family. Like most MMPs, it is secreted as an inactive pro-form. MMP-13 has a predicted molecular weight around 54 kDa. It is activated once the pro-domain is cleaved, leaving an active enzyme composed of the catalytic domain and the hemopexin-like domain PDB: 1PEX. Although the actual mechanism has not been described, the hemopexin domain participates in collagen degradation, the catalytic domain alone being particularly inefficient in collagen degradation. During embryonic development, MMP-13 is expressed in the skeleton as required for restructuring the collagen matrix for bone mineralization. In pathological situations it is highly overexpressed; this occurs in human carcinomas, rheumatoid arthritis and osteoarthritis.
Matrix metalloproteinase-12 (MMP-12) also known as macrophage metalloelastase (MME) or macrophage elastase (ME) is an enzyme that in humans is encoded by the MMP12 gene.
Matrix metalloproteinase-26 also known as matrilysin-2 and endometase is an enzyme that in humans is encoded by the MMP26 gene.
Matrix metalloproteinase-19 (MMP-19) also known as matrix metalloproteinase RASI is an enzyme that in humans is encoded by the MMP19 gene.
Neutrophil collagenase, also known as matrix metalloproteinase-8 (MMP-8) or PMNL collagenase (MNL-CL), is a collagen cleaving enzyme which is present in the connective tissue of most mammals. In humans, the MMP-8 protein is encoded by the MMP8 gene. The gene is part of a cluster of MMP genes which localize to chromosome 11q22.3. Most MMP's are secreted as inactive proproteins which are activated when cleaved by extracellular proteinases. However, the enzyme encoded by this gene is stored in secondary granules within neutrophils and is activated by autolytic cleavage.
Matrix metalloproteinase 15 also known as MMP15 is an enzyme that in humans is encoded by the MMP15 gene.
In molecular biology, the CHAP domain is a region between 110 and 140 amino acids that is found in proteins from bacteria, bacteriophages, archaea and eukaryotes of the family Trypanosomidae. The domain is named after the acronym cysteine, histidine-dependent amidohydrolases/peptidases. Many of these proteins are uncharacterised, but it has been proposed that they may function mainly in peptidoglycan hydrolysis. The CHAP domain is found in a wide range of protein architectures; it is commonly associated with bacterial type SH3 domains and with several families of amidase domains. It has been suggested that CHAP domain containing proteins utilise a catalytic cysteine residue in a nucleophilic-attack mechanism.
In molecular biology, VanY are protein domains found in enzymes named metallopeptidases. They are vital to bacterial cell wall synthesis and antibiotic resistance.
Muramoylpentapeptide carboxypeptidase is an enzyme. This enzyme catalyses the following chemical reaction.
Zinc D-Ala-D-Ala carboxypeptidase (EC 3.4.17.14, Zn2+ G peptidase, D-alanyl-D-alanine hydrolase, D-alanyl-D-alanine-cleaving carboxypeptidase, DD-carboxypeptidase, G enzyme, DD-carboxypeptidase-transpeptidase) is an enzyme. This enzyme catalyses the following chemical reaction