Protein Family Models

This is the very C-terminal, chaperone, domain of the bacteriophage protein endosialidase. It releases itself, via the serine-lysine dyad at the N-terminus, from the remainder of the end-tail-spike. Cleavage occurs after the threonine which is the final residue of the End-tail-spike family, Pfam:PF12219. The endosialidase protein forms homotrimeric molecules in bacteriophages [1]. The catalytic dyad allows this portion of the molecule to be cleaved from the more N-terminal region such that the latter can fold and bind to polysialic acid in the bacterial outer envelope [1]. [1]. 17158460. Characterization of a novel intramolecular chaperone domain conserved in endosialidases and other bacteriophage tail spike and fiber proteins. Schwarzer D, Stummeyer K, Gerardy-Schahn R, Muhlenhoff M;. J Biol Chem. 2007;282:2821-2831. (from Pfam)

Date:

2024-10-16

This domain family is found in bacteria and viruses, and is approximately 80 amino acids in length.This domain is the beta barrel domain of bacteriophage endosialidase which represents the one of the two sialic acid binding sites of the enzyme. The domain is nested in the beta propeller domain of the endosialidase enzyme. The endosialidase protein complexes to form homotrimeric molecules. [1]. 15608653. Crystal structure of the polysialic acid-degrading endosialidase of bacteriophage K1F. Stummeyer K, Dickmanns A, Muhlenhoff M, Gerardy-Schahn R, Ficner R;. Nat Struct Mol Biol. 2005;12:90-96. (from Pfam)

Date:

2024-10-16

This domain family is found in bacteria and viruses, and is approximately 160 amino acids in length. There are two conserved sequence motifs: VSR and YGA. This domain is the C terminal domain of the bacteriophage protein endosialidase. The endosialidase protein forms homotrimeric molecules and this domain complexes into a tail-spike stalk. The stalk region folds in a triple beta-helix that is interrupted by a small triple beta-prism domain. The tail-spike is a multifunctional protein device used by the phage to fulfill the following functions: (i) to adsorb to the bacterial polySia capsule (ii) to de-polymerise the capsule to gain access to the outer bacterial membrane, and finally (iii) to mediate tight adhesion to the membrane, a prerequisite for the initiation of the infection cycle. [1]. 15608653. Crystal structure of the polysialic acid-degrading endosialidase of bacteriophage K1F. Stummeyer K, Dickmanns A, Muhlenhoff M, Gerardy-Schahn R, Ficner R;. Nat Struct Mol Biol. 2005;12:90-96. (from Pfam)

Date:

2024-10-16

This domain family is found in bacteria and viruses, and is typically between 443 and 460 amino acids in length. This domain is the highly conserved beta propeller of bacteriophage endosialidase which represents the catalytically active part of the enzymes. This core domain forms stable SDS-resistant trimers. There is a nested beta barrel domain in this domain (Pfam:PF12195). The endosialidase protein complexes to form a homotrimeric molecule. [1]. 15608653. Crystal structure of the polysialic acid-degrading endosialidase of bacteriophage K1F. Stummeyer K, Dickmanns A, Muhlenhoff M, Gerardy-Schahn R, Ficner R;. Nat Struct Mol Biol. 2005;12:90-96. (from Pfam)

Date:

2024-10-16