Protein Family Models

This family includes helix-turn-helix domains in a wide variety of proteins. (from Pfam)

Date:

2024-08-14

This family includes biotin protein ligase, lipoate-protein ligase A and B. Biotin is covalently attached at the active site of certain enzymes that transfer carbon dioxide from bicarbonate to organic acids to form cellular metabolites. Biotin protein ligase (BPL) is the enzyme responsible for attaching biotin to a specific lysine at the active site of biotin enzymes. Each organism probably has only one BPL. Biotin attachment is a two step reaction that results in the formation of an amide linkage between the carboxyl group of biotin and the epsilon-amino group of the modified lysine [2]. Lipoate-protein ligase A (LPLA) catalyses the formation of an amide linkage between lipoic acid and a specific lysine residue in lipoate dependent enzymes [3]. The unusual biosynthesis pathway of lipoic acid is mechanistically intertwined with attachment of the cofactor [5]. [1]. 1409631. Escherichia coli biotin holoenzyme synthetase/bio repressor crystal structure delineates the biotin- and DNA-binding domains. Wilson KP, Shewchuk LM, Brennan RG, Otsuka AJ, Matthews BW;. Proc Natl Acad Sci USA 1992;89:9257-9261. A comprehensive review of biotinylation. [2]. 10470036. The enzymatic biotinylation of proteins: a post-translational modification of exceptional specificity. Chapman-Smith A, Cronan JE Jr;. Trends Biochem Sci 1999;24:359-363. [3]. 8206909. Identification of the gene encoding lipoate-protein ligase A of Escherichia coli. Molecular cloning and characterization of the lplA gene and gene product. Morris TW, Reed KE, Cronan JE Jr;. J Biol Chem 1994;269:16091-16100. [4]. 11106165. Lipoylating and biotinylating enzymes contain a homo. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

The function of this structural domain is unknown. It is found to the C terminus of the biotin protein ligase catalytic domain Pfam:PF01317. (from Pfam)

Date:

2024-08-14

Gene:

birA

Date:

2022-06-03

bifunctional biotin--[acetyl-CoA-carboxylase] ligase/biotin operon repressor BirA acts both as a biotin--[acetyl-CoA-carboxylase] ligase and a biotin-operon repressor, forming a BirA-biotinyl-5'-adenylate complex that can either transfer the biotinyl moiety to the BCCP subunit of acetyl-CoA carboxylase, or bind to the biotin operator site and inhibit transcription of the operon

Date:

2023-03-21

This model represents the biotin--acetyl-CoA-carboxylase ligase region of biotin--acetyl-CoA-carboxylase ligase. In Escherichia coli and some other species, this enzyme is part of a bifunction protein BirA that includes a small, N-terminal biotin operon repressor domain. Proteins identified by this model should not be called bifunctional unless they are also identified by birA_repr_reg (TIGR00122). The protein name suggests that this enzyme transfers biotin only to acetyl-CoA-carboxylase but it also transfers the biotin moiety to other proteins. The apparent orthologs among the eukaryotes are larger proteins that contain a single copy of this domain.

Date:

2022-06-03