Protein Family Models

NeuB is the prokaryotic N-acetylneuraminic acid (Neu5Ac) synthase. It catalyses the direct formation of Neu5Ac (the most common sialic acid) by condensation of phosphoenolpyruvate (PEP) and N-acetylmannosamine (ManNAc). This reaction has only been observed in prokaryotes; eukaryotes synthesise the 9-phosphate form, Neu5Ac-9-P, and utilise ManNAc-6-P instead of ManNAc. Such eukaryotic enzymes are not present in this family [1]. This family also contains SpsE spore coat polysaccharide biosynthesis proteins. [1]. 10873658. Molecular cloning and expression of the mouse N-acetylneuraminic acid 9-phosphate synthase which does not have deaminoneuraminic acid (KDN) 9-phosphate synthase activity. Nakata D, Close BE, Colley KJ, Matsuda T, Kitajima K;. Biochem Biophys Res Commun 2000;273:642-648. (from Pfam)

Date:

2024-10-16

Chorismate mutase EC:5.4.99.5 catalyses the conversion of chorismate to prephenate in the pathway of tyrosine and phenylalanine biosynthesis. This enzyme is negatively regulated by tyrosine, tryptophan and phenylalanine [2,3]. [1]. 7971967. The crystal structure of allosteric chorismate mutase at 2.2-A resolution. Xue Y, Lipscomb WN, Graf R, Schnappauf G, Braus G;. Proc Natl Acad Sci U S A 1994;91:10814-10818. [2]. 9642265. Tyrosine and tryptophan act through the same binding site at the dimer interface of yeast chorismate mutase. Schnappauf G, Krappmann S, Braus GH;. J Biol Chem 1998;273:17012-17017. [3]. 9497350. Chorismate mutase-prephenate dehydratase from Escherichia coli. Study of catalytic and regulatory domains using genetically engineered proteins. Zhang S, Pohnert G, Kongsaeree P, Wilson DB, Clardy J, Ganem B;. J Biol Chem 1998;273:6248-6253. (from Pfam)

Date:

2024-10-16

Members of this family catalyse the first step in aromatic amino acid biosynthesis from chorismate. E-coli has three related synthetases, which are inhibited by different aromatic amino acids. This family also includes KDSA which has very similar catalytic activity but is involved in the first step of liposaccharide biosynthesis. The enzyme is also part of the shikimate pathway, EC:2.5.1.54. [1]. 10425687. Crystal structure of phenylalanine-regulated 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase from Escherichia coli. Shumilin IA, Kretsinger RH, Bauerle RH;. Structure Fold Des 1999;7:865-875. (from Pfam)

Date:

2024-10-16

Catalyzes the formation of 3-deoxy-D-arabino-hept-2-ulosonate 7-phosphate from phosphoenolpyruvate and D-erythrose 4-phosphate

Date:

2020-10-26

This model represents a small clade of chorismate mutase domains N-terminally fused to the first enzyme in the chorismate pathway, 2-dehydro-3-deoxyphosphoheptanoate aldolase (DAHP synthetase, AroA) which are found in some gram positive species and Deinococcus. Only in Deinococcus, where this domain is the sole CM domain in the genome can a trusted assignment of function be made. In the other species there is at least one other trusted CM domain present. The similarity between the Deinococcus gene and the others in this clade is sufficiently strong (~44% identity), that the whole clade can be trusted to be functional. The possibility exists, however, that in the gram positive species the fusion to the first enzyme in the pathway has evolved a separate, regulatory role.

Gene:

aroA

Date:

2019-09-10

This model describes one of at least three types of phospho-2-dehydro-3-deoxyheptonate aldolase (DAHP synthase). This enzyme catalyzes the first of 7 steps in the biosynthesis of chorismate, that last common precursor of all three aromatic amino acids and of PABA, ubiquinone and menaquinone. Some members of this family, including an experimentally characterized member from Bacillus subtilis, are bifunctional, with a chorismate mutase domain N-terminal to this region. The member of this family from Synechocystis PCC 6803, CcmA, was shown to be essential for carboxysome formation. However, no other candidate for this enzyme is present in that species, chorismate biosynthesis does occur, other species having this protein lack carboxysomes but appear to make chorismate, and a requirement of CcmA for carboxysome formation does not prohibit a role in chorismate biosynthesis.

Gene:

aroF

Date:

2021-04-27

bifunctional 3-deoxy-7-phosphoheptulonate synthase/chorismate mutase is involved in chorismate biosynthesis and prephenate biosynthesis

Date:

2019-07-26

Catalyzes the formation of 3-deoxy-D-aribino-hept-2-ulosonate 7-phosphate from phosphoenolpyruvate and D-erythrose 4-phosphate and the formation of prephenate from chorismate

Date:

2021-09-22