Crystallographic phasing of myristoyl-CoA-protein N-myristoyltransferase using an iodinated analog of myristoyl-CoA.
Myristoyl-CoA-protein N-myristoyltransferase (Nmt; E.C. 2.1.3.97) catalyzes the covalent attachment of myristate to the N-terminal glycine amine of many eukaryotic and viral proteins. The molecular structure of the ternary complex of Saccharomyces cerevisiae Nmt1p with a bound non-hydrolyzable myristoyl-CoA analog, S-(2-oxopentadecyl)-CoA, and a competitive peptidomimetic inhibitor, SC-58272, was solved to 2.9 A resolution by X-ray crystallography. The structure determination utilized diffraction data from an iodinated ternary complex in which a newly designed and synthesized compound, S-(13-iodo-2-oxotridecyl)-CoA, was substituted for S-(2-oxopentadecyl)-CoA. Replacing the two terminal fatty acid C atoms of myristate by iodine produced, under the same crystallization conditions, heavy-atom-derivatized crystals of defined site occupancy that were isomorphous to the native complex. This approach for obtaining experimental phase information can be extended to other crystal structures of protein-fatty acyl complexes. The synthesis of S-(13-iodo-2-oxotridecyl)-CoA and the phasing procedure are described.
Department of Biochemistry and Molecular Biophysics, Wahsington University School of Medicine, Saint Louis, MO 63110, USA.
K
K
Fütterer
C L
CL
Murray
R S
RS
Bhatnagar
G W
GW
Gokel
J I
JI
Gordon
G
G
Waksman
D000214:Acyl Coenzyme A / Q000737:chemistry*; D000217:Acyltransferases / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D004583:Electrons; D007455:Iodine / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D000214:Acyl Coenzyme A; C040349:S-tetradecanoyl-coenzyme A; D007455:Iodine; D000217:Acyltransferases; C050480:glycylpeptide N-tetradecanoyltransferase