Dihydropteroate synthase is an enzyme classified under . It produces
dihydropteroate
Dihydropteroate is an important intermediate in folate synthesis. It is a pterin created from ''para''-aminobenzoic acid (PABA) by the enzyme dihydropteroate synthase.
Bacteriostatic agents such as sulfonamides target dihydropteroate synthetas ...
in
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
, but it is not expressed in most
eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...
s including humans. This makes it a useful target for
sulfonamide
In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. ...
antibiotics, which compete with the
PABA precursor.
*
(2-amino-4-hydroxy-7,8-dihydropteridin-6-yl)methyl diphosphate +
4-aminobenzoate (PABA)
diphosphate +
dihydropteroate
Dihydropteroate is an important intermediate in folate synthesis. It is a pterin created from ''para''-aminobenzoic acid (PABA) by the enzyme dihydropteroate synthase.
Bacteriostatic agents such as sulfonamides target dihydropteroate synthetas ...
.
All organisms require reduced folate cofactors for the synthesis of a variety of metabolites. Most microorganisms must synthesize folate de novo because they lack the active transport system of
higher vertebrate
Amniotes are a clade of tetrapod vertebrates that comprises sauropsids (including all reptiles and birds, and extinct parareptiles and non-avian dinosaurs) and synapsids (including pelycosaurs and therapsids such as mammals). They are distingu ...
cells that allows these organisms to use dietary folates. Proteins containing this domain include dihydropteroate synthase () as well as a group of methyltransferase enzymes including methyltetrahydrofolate, corrinoid iron-sulphur protein methyltransferase (MeTr)
that catalyses a key step in the
Wood-Ljungdahl pathway of carbon dioxide fixation.
Dihydropteroate synthase () (DHPS) catalyses the condensation of 6-hydroxymethyl-7,8-dihydropteridine pyrophosphate to para-aminobenzoic acid to form 7,8-dihydropteroate. This is the second step in the three-step pathway leading from 6-hydroxymethyl-7,8-dihydropterin to 7,8-dihydrofolate. DHPS is the target of sulfonamides, which are substrate analogues that compete with para-aminobenzoic acid. Bacterial DHPS (gene sul or folP)
is a protein of about 275 to 315 amino acid residues that is either chromosomally encoded or found on various
antibiotic resistance
Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. ...
plasmids. In the fungus ''
Pneumocystis jirovecii
''Pneumocystis jirovecii'' (previously ''P. carinii'') is a yeast-like fungus of the genus ''Pneumocystis''. The causative organism of ''Pneumocystis'' pneumonia, it is an important human pathogen, particularly among immunocompromised hosts. Pr ...
'' (previously ''P. carinii'') DHPS is the C-terminal domain of a multifunctional folate synthesis enzyme (gene fas).
References
External links
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EC 2.5.1
{{2.5-enzyme-stub