1qzf: Difference between revisions

[[Image:1qzf.gif|left|200px]]<br /><applet load="1qzf" size="350" color="white" frame="true" align="right" spinBox="true"  

We have determined the crystal structure of dihydrofolate reductase-thymidylate synthase (DHFR-TS) from Cryptosporidium hominis, revealing a unique linker domain containing an 11-residue alpha-helix that has extensive interactions with the opposite DHFR-TS monomer of the homodimeric enzyme. Analysis of the structure of DHFR-TS from C. hominis and of previously solved structures of DHFR-TS from Plasmodium falciparum and Leishmania major reveals that the linker domain primarily controls the relative orientation of the DHFR and TS domains. Using the tertiary structure of the linker domains, we have been able to place a number of protozoa in two distinct and dissimilar structural families corresponding to two evolutionary families and provide the first structural evidence validating the use of DHFR-TS as a tool of phylogenetic classification. Furthermore, the structure of C. hominis DHFR-TS calls into question surface electrostatic channeling as the universal means of dihydrofolate transport between TS and DHFR in the bifunctional enzyme.

1QZF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cryptosporidium_hominis Cryptosporidium hominis] with <scene name='pdbligand=UMP:'>UMP</scene>, <scene name='pdbligand=CB3:'>CB3</scene>, <scene name='pdbligand=FOL:'>FOL</scene> and <scene name='pdbligand=NDP:'>NDP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QZF OCA].  

[[Category: Anderson, A C.]]

[[Category: Donald, B R.]]

[[Category: Lilien, R H.]]

[[Category: Neil, R H.O.]]

[[Category: Stroud, R M.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:45:24 2008''