1e7w
From Proteopedia
One active site, two modes of reduction correlate the mechanism of leishmania pteridine reductase with pterin metabolism and antifolate drug resistance in trpanosomes
Structural highlights
FunctionPTR1_LEIMA Exhibits a NADPH-dependent biopterin reductase activity. Has good activity with folate and significant activity with dihydrofolate and dihydrobiopterin, but not with quinonoid dihydrobiopterin. Confers resistance to methotrexate (MTX).[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPteridine reductase (PTR1) is a short-chain reductase (SDR) responsible for the salvage of pterins in parasitic trypanosomatids. PTR1 catalyzes the NADPH-dependent two-step reduction of oxidized pterins to the active tetrahydro-forms and reduces susceptibility to antifolates by alleviating dihydrofolate reductase (DHFR) inhibition. Crystal structures of PTR1 complexed with cofactor and 7,8-dihydrobiopterin (DHB) or methotrexate (MTX) delineate the enzyme mechanism, broad spectrum of activity and inhibition by substrate or an antifolate. PTR1 applies two distinct reductive mechanisms to substrates bound in one orientation. The first reduction uses the generic SDR mechanism, whereas the second shares similarities with the mechanism proposed for DHFR. Both DHB and MTX form extensive hydrogen bonding networks with NADP(H) but differ in the orientation of the pteridine. Pteridine reductase mechanism correlates pterin metabolism with drug resistance in trypanosomatid parasites.,Gourley DG, Schuttelkopf AW, Leonard GA, Luba J, Hardy LW, Beverley SM, Hunter WN Nat Struct Biol. 2001 Jun;8(6):521-5. PMID:11373620[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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