Methylglyoxal synthase (MGS, EC 4.2.3.3) (see <PDOC01037>), which catalyzes the conversion of dihydroxyacetone phosphate (DHAP) to methylglyoxal (MG) and inorganic phosphate, has been found in many organisms, including enteric bacteria, some gram-positive bacteria, a number of archaebacteria, several yeast species and goat liver [1,2]. A domain similar to the full-length MGS is found in [3]:

• Bifunctional purine biosynthesis protein PurH, also known as aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase (AICAR Tfase)/inosine 50-monophosphate (IMP) cyclohydrolase (IMPCH) (ATIC) (EC 2.1.2.3). In bacteria and eukaryotes, the last two steps of de novo purine biosynthesis are catalyzed by PurH, which is composed of two functionally independent domains linked by a flexible region. The N- terminal MGS-like domain possesses IMPCH activity and the C-terminal domain possesses AICAR Tfase activity. The MGS-like domain with IMPCH activity catalyzes the intramolecular cyclization of 5-formyl-AICAR (FAICAR) to IMP [4,5,6,7].
• Carbamoyl phosphate synthetase (CPS) catalyzes the formation of carbamoyl phosphate from one molecule of bicarbonate, two molecules of Mg(2+)ATP and one molecule of glutamine or ammonia depending upon the particular form of the enzyme. The enzyme is an α,β-heterodimer consisting of a small subunit that hydrolyzes glutamine and a large subunit that catalyzes the two required phosphorylation events. The large subunit consists of four structural units: the carboxyphosphate synthetic component, the oligomerization domain, the carbamoyl phosphate synthetic component and the MGS-like allosteric domain. The binding of various ligands by the MGS-like domain allosterically regulates CPS [8,9].

The main core of the MGS-like domain, a modified 'Rossmann' fold, is characterized by a five stranded parallel β-sheet flanked on either side by three and five α-helices, respectively (see <PDB:1PKX>) [6,8]. MGS-like domains share a conserved phosphate binding site [3,7].

The profile we developed covers the entire MGS-like domain.