5dfr

<table><tr><td colspan='2'>[[5dfr]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5DFR OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=5DFR FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Dihydrofolate_reductase Dihydrofolate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.1.3 1.5.1.3] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=5dfr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5dfr OCA], [http://pdbe.org/5dfr PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5dfr RCSB], [http://www.ebi.ac.uk/pdbsum/5dfr PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5dfr ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/DYR_ECOLI DYR_ECOLI]] Key enzyme in folate metabolism. Catalyzes an essential reaction for de novo glycine and purine synthesis, and for DNA precursor synthesis.

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== Publication Abstract from PubMed ==

The crystal structure of unliganded dihydrofolate reductase (DHFR) from Escherichia coli has been solved and refined to an R factor of 19% at 2.3-A resolution in a crystal form that is nonisomorphous with each of the previously reported E. coli DHFR crystal structures [Bolin, J. T., Filman, D. J., Matthews, D. A., Hamlin, B. C., &amp; Kraut, J. (1982) J. Biol. Chem. 257, 13650-13662; Bystroff, C., Oatley, S. J., &amp; Kraut, J. (1990) Biochemistry 29, 3263-3277]. Significant conformational changes occur between the apoenzyme and each of the complexes: the NADP+ holoenzyme, the folate-NADP+ ternary complex, and the methotrexate (MTX) binary complex. The changes are small, with the largest about 3 A and most of them less than 1 A. For simplicity a two-domain description is adopted in which one domain contains the NADP+ 2'-phosphate binding site and the binding sites for the rest of the coenzyme and for the substrate lie between the two domains. Binding of either NADP+ or MTX induces a closing of the PABG-binding cleft and realignment of alpha-helices C and F which bind the pyrophosphate of the coenzyme. Formation of the ternary complex from the holoenzyme does not involve further relative domain shifts but does involve a shift of alpha-helix B and a floppy loop (the Met-20 loop) that precedes alpha B. These observations suggest a mechanism for cooperativity in binding between substrate and coenzyme wherein the greatest degree of cooperativity is expressed in the transition-state complex. We explore the idea that the MTX binary complex in some ways resembles the transition-state complex.

Crystal structure of unliganded Escherichia coli dihydrofolate reductase. Ligand-induced conformational changes and cooperativity in binding.,Bystroff C, Kraut J Biochemistry. 1991 Feb 26;30(8):2227-39. PMID:1998681<ref>PMID:1998681</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 5dfr" style="background-color:#fffaf0;"></div>

*[[Molecular Playground/DHFR|Molecular Playground/DHFR]]

== References ==

<references/>

[[Category: Bacillus coli migula 1895]]

[[Category: Dihydrofolate reductase]]

[[Category: Bystroff, C]]

[[Category: Kraut, J]]

[[Category: Oxidoreductase]]