HMM Summary Page: TIGR03128

Function3-hexulose-6-phosphate synthase
Gene SymbolhxlA
Trusted Cutoff243.40
Domain Trusted Cutoff243.40
Noise Cutoff146.85
Domain Noise Cutoff146.85
Isology Typeequivalog_domain
EC Number4.1.2.43
HMM Length206
AuthorHaft DH
Entry DateOct 30 2006 1:13PM
Last ModifiedFeb 14 2011 3:27PM
CommentMembers of this protein family are 3-hexulose-6-phosphate synthase (HPS), or the HPS domain of a fusion protein. This enzyme is part of the ribulose monophosphate (RuMP) pathway, which in one direction removes the toxic metabolite formaldehyde by assimilation into fructose-6-phosphate. In the other direction, in species lacking a complete pentose phosphate pathway, the RuMP pathway yields ribulose-5-phosphate, necessary for nucleotide biosynthesis, at the cost of also yielding formaldehyde. These latter species tend usually have a formaldehyde-activating enzyme to attach formaldehyde to the C1 carrier tetrahydromethanopterin. In these species, the enzyme is viewed as a lyase rather than a synthase and is called D-arabino 3-hexulose 6-phosphate formaldehyde lyase. Note that there is some overlap in specificity with the Escherichia coli enzyme 3-keto-L-gulonate 6-phosphate decarboxylase.
ReferencesRN [1] RM PMID: 15978081 RT HxlR, a member of the DUF24 protein family, is a DNA-binding protein that acts as a positive regulator of the formaldehyde-inducible hxlAB operon in Bacillus subtilis. RA Yurimoto H, Hirai R, Matsuno N, Yasueda H, Kato N, Sakai Y RL Mol Microbiol. 2005 Jul;57(2):511-9. RN [2] RM PMID: 15697207 RT Evolution of enzymatic activities in the orotidine 5'-monophosphate decarboxylase suprafamily: structural basis for catalytic promiscuity in wild-type and designed mutants of 3-keto-L-gulonate 6-phosphate decarboxylase. RA Wise EL, Yew WS, Akana J, Gerlt JA, Rayment I RL Biochemistry. 2005 Feb 15;44(6):1816-23.
Genome PropertyGenProp0673: ribulose monophosphate pathway (HMM)