Literature summary for 4.1.99.17 extracted from

Hwang, S.; Cordova, B.; Abdo, M.; Pfeiffer, F.; Maupin-Furlow, J.-A.
ThiN as a versatile domain of transcriptional repressors and catalytic enzymes of thiamine biosynthesis (2017), J. Bacteriol., 199, pii: e00810-16 .

Search for more literature for 4.1.99.17

Cloned(Commentary)

Cloned (Comment)	Organism
gene thiC, archaeal ThiC is encoded by leaderless transcripts, ruling out a riboswitch mechanism. Instead, transcription factor ThiR, that harbors an N-terminal helix-turn-helix (HTH) DNA binding domain and C-terminal ThiN (TMP synthase) domain, is identified. In the presence of thiamine, ThiR represses the expression of thiC by a DNA operator sequence that is conserved across archaeal phyla. Sequence comparisons and genetic organization analysis	Haloferax volcanii

Cloned (Comment)

Organism

gene thiC, archaeal ThiC is encoded by leaderless transcripts, ruling out a riboswitch mechanism. Instead, transcription factor ThiR, that harbors an N-terminal helix-turn-helix (HTH) DNA binding domain and C-terminal ThiN (TMP synthase) domain, is identified. In the presence of thiamine, ThiR represses the expression of thiC by a DNA operator sequence that is conserved across archaeal phyla. Sequence comparisons and genetic organization analysis

Haloferax volcanii

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
5-amino-1-(5-phospho-D-ribosyl)imidazole + S-adenosyl-L-methionine	Haloferax volcanii	-	4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine + 5'-deoxyadenosine + L-methionine + formate + CO	-	?
5-amino-1-(5-phospho-D-ribosyl)imidazole + S-adenosyl-L-methionine	Haloferax volcanii ATCC 29605	-	4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine + 5'-deoxyadenosine + L-methionine + formate + CO	-	?

Organism

Organism	UniProt	Comment	Textmining
Haloferax volcanii	D4GV87	-	-
Haloferax volcanii ATCC 29605	D4GV87	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
5-amino-1-(5-phospho-D-ribosyl)imidazole + S-adenosyl-L-methionine	-	Haloferax volcanii	4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine + 5'-deoxyadenosine + L-methionine + formate + CO	-	?
5-amino-1-(5-phospho-D-ribosyl)imidazole + S-adenosyl-L-methionine	-	Haloferax volcanii ATCC 29605	4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine + 5'-deoxyadenosine + L-methionine + formate + CO	-	?

Synonyms

Synonyms	Comment	Organism
2-methyl-4-amino-5-hydroxymethylpyrimidine phosphate synthase	-	Haloferax volcanii
HMP phosphate synthase	-	Haloferax volcanii
HMP-P synthase	-	Haloferax volcanii
thiC	-	Haloferax volcanii

Cofactor

Cofactor	Comment	Organism	Structure
S-adenosyl-L-methionine	-	Haloferax volcanii

Expression

Organism	Comment	Expression
Haloferax volcanii	transcription factor ThiR, that harbors an N-terminal helix-turn-helix (HTH) DNA binding domain and C-terminal ThiN (TMP synthase) domain, represses the expression of thiC in presence of thiamine by a DNA operator sequence that is conserved across archaeal phyla. Despite having a ThiN domain, ThiR is catalytically inactive in compensating for the loss of ThiE (TMP synthase) function. ThiR homologs are widespread in archaea, suggesting that the regulation of these thiamine biosynthesis genes is governed by a repressor protein and not by a riboswitch or activation mechanism	down

General Information

General Information	Comment	Organism
malfunction	a DELTAthiC mutant displays thiamine auxotrophy, the phenotype is not due to polar mutations, as the strain is restored to wild-type growth by the expression of the corresponding thiC gene in trans	Haloferax volcanii
metabolism	in the archaeon Haloferax volcanii, thiamine biosynthesis is carried out by a chimera of the eukaryote-like THI4 pathway to synthesize the thiazole ring with a bacterial ThiC-like pathway to synthesize the pyrimidine (HMP) moiety. The enzyme ThiC is involved in thiamine biosynthesis. Haloferax volcanii uses a eukaryote-like Thi4 (thiamine thiazole synthase) for the production of the thiazole ring and condenses this ring with a pyrimidine moiety synthesized by an apparent bacterium-like ThiC (2-methyl-4-amino-5-hydroxymethylpyrimidine [HMP] phosphate synthase) branch. In the presence of thiamine, transcription factor ThiR represses the expression of thiC by a DNA operator sequence. Thiamine biosynthesis in archaea is regulated by a transcriptional repressor, ThiR, and not by a riboswitch. In archaea, thiamine biosynthesis is an apparent chimera of eukaryote- and bacterium-type pathways	Haloferax volcanii
physiological function	the enzyme ThiC is involved in thiamine biosynthesis. The archaeon Haloferax volcanii uses a eukaryote-like Thi4 (thiamine thiazole synthase) for the production of the thiazole ring and condenses this ring with a pyrimidine moiety synthesized by an apparent bacterium-like ThiC (2-methyl-4-amino-5-hydroxymethylpyrimidine [HMP] phosphate synthase) branch. In the presence of thiamine, transcription factor ThiR represses the expression of thiC by a DNA operator sequence. Thiamine biosynthesis in archaea is regulated by a transcriptional repressor, ThiR, and not by a riboswitch, mechanims, overview	Haloferax volcanii