Protein Family Models

Escherichia coli and other enteric bacteria contain two closely related D-tagatose 1,6-bisphosphate (TagBP)-specific aldolases involved in catabolism of galactitol (genes gatY gatZ) and of N-acetyl-galactosamine and D-galactosamine (genes kbaY, kbaZ, also called agaY, agaZ). The catalytic subunits GatY/KbaY alone are sufficient to show aldolase activity and contain most or all of the residues that have been identified as essential in substrate/product recognition and catalysis for class II aldolases [1, 2]. However, these aldolases differ from other Class II aldolases (which are homodimeric enzymes) in that they require subunits GatZ/KbaZ for full activity and for good in vivo and in vitro stability. The Z subunits alone do not show any aldolase activity [1]. This entry represents GatZ and KbaZ subunits. This entry also includes the D-tagatose 6-phosphate 4-epimerase Atu3167 from Agrobacterium fabrum which catalyzes the epimerization of D-tagatose 6-phosphate to D-fructose 6-phosphate [3]. It should be noted that the previous suggestion of a tagatose 6P-kinase function for other members of this family has been debated [4, 1, 5]. [1]. 11976750. Two class II D-tagatose-bisphosphate aldolases from enteric bacteria. Brinkkotter A, Shakeri-Garakani A, Lengeler JW;. Arch Microbiol. 2002;177:410-419. [2]. 8955298. Molecular analysis of the gat genes from Escherichia coli and of their roles in galactitol transport and metabolism. Nobelmann B, Lengeler JW;. J Bacteriol. 1996;178:6790-6795. [3]. 26472925. ATP-binding Cassette (ABC) Transport System Solute-binding Protein-guided Identification of Novel d-Altritol and Galac. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

Gene:

kbaZ

Date:

2020-10-26

Aldolases specific for D-tagatose-bisphosphate occur in distinct pathways in Escherichia coli and other bacteria, one for the degradation of galactitol (formerly dulcitol) and one for degradation of N-acetyl-galactosamine and D-galactosamine. This family represents a protein of both systems that behaves as a non-catalytic subunit of D-tagatose-bisphosphate aldolase, required both for full activity and for good stability of the aldolase. Note that members of this protein family appear in public databases annotated as putative tagatose 6-phosphate kinases, possibly in error.

Date:

2024-06-27

tagatose-bisphosphate aldolase subunit KbaZ is a component of the tagatose-1,6-bisphosphate aldolase KbaYZ that is required for full activity and stability of the Y subunit

Date:

2019-08-06