1jmb
|
CRYSTAL STRUCTURE OF FOUR-HELIX BUNDLE MODEL
OverviewOverview
De novo design of proteins provides an attractive approach to uncover the, essential features required for their functions. Previously, we described, the design and crystal structure determination of a di-Zn(II) complex of, "due-ferri-1" (DF1), a protein patterned after the diiron-dimanganese, class of redox-active proteins [Lombardi, A.; Summa, C.; Geremia, S.;, Randaccio, L.; Pavone, V.; DeGrado, W. F. Proc. Natl. Acad. Sci. U.S.A., 2000, 97, 6298-6305]. The overall structure of DF1, which contains a, carboxylate-bridged dinuclear metal site, agrees well with the intended, design. However, access to this dimetal site is blocked by a pair of, hydrophobic leucine residues (L13 and L13'), which prevent facile entry of, metal ions and small molecules. We have now taken the next step in the, eventual construction of a catalytically active metalloenzyme by, engineering an active site cavity into DF1 through the replacement of, these two leucine residues with smaller residues. The crystal structure of, the dimanganous form of L13A-DF1 indeed shows a substrate access channel, to the dimetal center. In the crystal structure, water molecules and a, ligating dimethyl sulfoxide molecule, which forms a monatomic bridge, between the metal ions, occupy the cavity. Furthermore, the diferric form, of a derivative of L13A-DF1, DF2, is shown to bind azide, acetate, and, small aromatic molecules.
About this StructureAbout this Structure
1JMB is a Protein complex structure of sequences from [1] with MN, ACE, NH2 and DMS as ligands. The following page contains interesting information on the relation of 1JMB with [Designer Proteins]. Full crystallographic information is available from OCA.
ReferenceReference
Toward the de novo design of a catalytically active helix bundle: a substrate-accessible carboxylate-bridged dinuclear metal center., Di Costanzo L, Wade H, Geremia S, Randaccio L, Pavone V, DeGrado WF, Lombardi A, J Am Chem Soc. 2001 Dec 26;123(51):12749-57. PMID:11749531
Page seeded by OCA on Sun Nov 18 09:02:33 2007