{PDOC50263}
{PS50263; CN_HYDROLASE}
{BEGIN}
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* Carbon-nitrogen hydrolase domain profile *
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The carbon-nitrogen  hydrolase domain is an around 265-residue domain found in
numerous enzymes  involved  in the reduction of organic nitrogen compounds and
ammonia production.  Based  on  their sequence similarity and on the reactions
they catalyze,  these  enzymes  can  be  classified into functionally distinct
groups including [1,2]:

 - Nitrilases   (EC   3.5.5.1),   which   cleave  various  nitriles  into  the
   corresponding acids and ammonia (see <PDOC00712>).
 - Cyanide  hydratase  (EC 4.2.1.66) of pathogenic fungi, which detoxifies HCN
   that is  released  by  their  hosts,  cyanogenic  plants, after injury (see
   <PDOC00712>).
 - Aliphatic amidases (EC 3.5.1.4), which enable prokaryotes to use acetamides
   as both carbon and nitrogen source.
 - Beta-alanine    synthase    (N-carbamoyl-beta-alanine    amino   hydrolase)
   (EC 3.5.1.6), which catalyses the last step of pyrimidine catabolism.
 - AdgA  (for ammonia-dependent growth) from Rhodobacter species (EC 6.3.5.1).
   It appears  to  be  essential  for  using  various  amino acids as nitrogen
   sources.
 - Biotinidase  (EC  3.5.1.12),  which catalyzes the hydrolysis of biocytin to
   biotin and lysine.
 - Pantetheinase   (EC 3.5.1.92)   (Pantetheine   hydrolase)  (Vanin),   which
   hydrolyzes specifically  one  of  the carboamide linkages in D-pantetheine,
   thus recycling pantothenic acid (vitamin B5) and releasing cysteamine.
 - Apolipoprotein  N-acyltransferase   (EC  2.3.1.-)  (gene  lnt), a bacterial
   enzyme that transfers the fatty acyl group on membrane lipoproteins.

The carbon-nitrogen  hydrolase  domain  can  be found alone or associated with
other domains,  such  as the NAD synthase domain, the HIT histidine triad (see
<PDOC00694>), the acetyltransferase domain or the glycosyltransferase domain.

The carbon-nitrogen  hydrolase  domain  is  characterized by several conserved
motifs, one  of  which contains a cysteines that is part of the catalytic site
in nitrilases.  Another  highly  conserved motif includes a glutamic acid that
might also be involved in catalysis [1].

The profile we developed covers the entire carbon-nitrogen hydrolase domain.

-Sequences known to belong to this class detected by the profile: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Last update: March 2017 / Profile revised.

[ 1] Bork P., Koonin E.V.
     "A new family of carbon-nitrogen hydrolases."
     Protein Sci. 3:1344-1346(1994).
     PubMed=7987228
[ 2] Fujii T., Ahn J.-Y., Kuse M., Mori H., Matsuda T., Isobe M.
     "A novel photoprotein from oceanic squid (Symplectoteuthis
     oualaniensis) with sequence similarity to mammalian carbon-nitrogen
     hydrolase domains."
     Biochem. Biophys. Res. Commun. 293:874-879(2002).
     PubMed=12054553; DOI=10.1016/S0006-291X(02)00296-6

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