View source for 4keb


==Human dihydrofolate reductase complexed with NADPH and 5-{3-[3-methoxy-5-(isoquin-5-yl)phenyl]but-1-yn-1-yl}6-ethylpyrimidine-2,4-diamine==
<StructureSection load='4keb' size='340' side='right'caption='[[4keb]], [[Resolution|resolution]] 1.45&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4keb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4KEB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4KEB FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.45&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1QZ:6-ETHYL-5-{(3S)-3-[3-(ISOQUINOLIN-5-YL)-5-METHOXYPHENYL]BUT-1-YN-1-YL}PYRIMIDINE-2,4-DIAMINE'>1QZ</scene>, <scene name='pdbligand=FOL:FOLIC+ACID'>FOL</scene>, <scene name='pdbligand=NDP:NADPH+DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NDP</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4keb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4keb OCA], [https://pdbe.org/4keb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4keb RCSB], [https://www.ebi.ac.uk/pdbsum/4keb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4keb ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/DYR_HUMAN DYR_HUMAN] Defects in DHFR are the cause of megaloblastic anemia due to dihydrofolate reductase deficiency (DHFRD) [MIM:[https://omim.org/entry/613839 613839]. DHFRD is an inborn error of metabolism, characterized by megaloblastic anemia and/or pancytopenia, severe cerebral folate deficiency, and cerebral tetrahydrobiopterin deficiency. Clinical features include variable neurologic symptoms, ranging from severe developmental delay and generalized seizures in infancy, to childhood absence epilepsy with learning difficulties, to lack of symptoms.<ref>PMID:21310276</ref> <ref>PMID:21310277</ref> 
== Function ==
[https://www.uniprot.org/uniprot/DYR_HUMAN DYR_HUMAN] Key enzyme in folate metabolism. Contributes to the de novo mitochondrial thymidylate biosynthesis pathway. Catalyzes an essential reaction for de novo glycine and purine synthesis, and for DNA precursor synthesis. Binds its own mRNA and that of DHFRL1.<ref>PMID:21876188</ref> <ref>PMID:12096917</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The pursuit of antimicrobial drugs that target dihydrofolate reductase (DHFR) exploits differences in sequence and dynamics between the pathogenic and human enzymes. Here, we present five crystal structures of human DHFR bound to a new class of antimicrobial agents, the propargyl-linked antifolates (PLAs), with a range of potency (IC50 values of 0.045-1.07 muM) for human DHFR. These structures reveal that interactions between the ligands and Asn 64, Phe 31, and Phe 34 are important for increased affinity for human DHFR and that loop residues 58-64 undergo ligand-induced conformational changes. The utility of these structural studies was demonstrated through the design of three new ligands that reduce the number of contacts with Asn 64, Phe 31, and Phe 34. Synthesis and evaluation show that one of the designed inhibitors exhibits the lowest affinity for human DHFR of any of the PLAs (2.64 muM). Comparisons of structures of human and Staphylococcus aureus DHFR bound to the same PLA reveal a conformational change in the ligand that enhances interactions with residues Phe 92 (Val 115 in huDHFR) and Ile 50 (Ile 60 in huDHFR) in S. aureus DHFR, yielding selectivity. Likewise, comparisons of human and Candida glabrata DHFR bound to the same ligand show that hydrophobic interactions with residues Ile 121 and Phe 66 (Val 115 and Asn 64 in human DHFR) yield selective inhibitors. The identification of residue substitutions that are important for selectivity and the observation of active site flexibility will help guide antimicrobial antifolate development for the inhibition of pathogenic species.

Elucidating Features That Drive the Design of Selective Antifolates Using Crystal Structures of Human Dihydrofolate Reductase.,Lamb KM, G-Dayanandan N, Wright DL, Anderson AC Biochemistry. 2013 Oct 3. PMID:24053334<ref>PMID:24053334</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4keb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Dihydrofolate reductase 3D structures|Dihydrofolate reductase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Anderson AC]]
[[Category: Lamb KM]]