HMM Summary Page: TIGR01513

Functionnicotinate phosphoribosyltransferase
Gene SymbolpncB
Trusted Cutoff297.40
Domain Trusted Cutoff297.40
Noise Cutoff119.20
Domain Noise Cutoff119.20
Isology Typehypoth_equivalog
EC Number6.3.4.21
HMM Length452
Mainrole CategoryBiosynthesis of cofactors, prosthetic groups, and carriers
Subrole CategoryPyridine nucleotides
Gene Ontology TermGO:0004516: nicotinate phosphoribosyltransferase activity molecular_function
GO:0019357: nicotinate nucleotide biosynthetic process biological_process
GO:0019358: nicotinate nucleotide salvage biological_process
AuthorHaft DH
Entry DateMay 20 2002 1:56PM
Last ModifiedFeb 25 2011 12:36PM
CommentA deep split separates two related families of proteins, one of which includes experimentally characterized examples of nicotinate phosphoribosyltransferase, an the first enzyme of NAD salvage biosynthesis. This HMM represents the other family. Members have a different (longer) spacing of several key motifs and have an additional C-terminal domain of up to 100 residues. One argument suggesting that this family represents the same enzyme is that no species has a member of both families. Another is that the gene encoding this protein is located near other NAD salvage biosynthesis genes in Nostoc and in at least four different Gram-positive bacteria. NAD and NADP are ubiquitous in life. Most members of this family are Gram-positive bacteria. An additional set of mutually closely related archaeal sequences score between the trusted and noise cutoffs.