1peh
From Proteopedia
|
NMR STRUCTURE OF THE MEMBRANE-BINDING DOMAIN OF CTP PHOSPHOCHOLINE CYTIDYLYLTRANSFERASE, 10 STRUCTURES
Overview
It has been proposed that the domain of the regulatory enzyme, CTP:phosphocholine cytidylyltransferase, which mediates reversible binding, of the enzyme to membranes, is an amphipathic alpha-helix of approximately, 60 amino acid residues and that this domain is adjacent to the putative, active site domain of this enzyme. Circular dichroism indicated that the, secondary structures of two overlapping peptides spanning this region were, predominantly alpha-helical in the presence of PG vesicles or sodium, dodecyl sulfate micelles. Interproton distances were obtained from, two-dimensional NMR spectroscopic measurements to solve the structures of, these two peptides. The C-terminal 22 amino acid peptide segment, (corresponding to Val267-Ser288) was a well-defined alpha-helix over its, length. The N-terminal 33-mer (corresponding to Asn236-Glu268) was, composed of an alpha-helix from Glu243 to Lys266, a well-structured bend, of about 50 degrees at Tyr240-His241-Leu242, and an N-terminal, four-residue helix. It is proposed that the three residues involved in, generating the bend act as the hinge between the catalytic and regulatory, domains. The nonpolar faces of the 33-mer and 22-mer were interrupted by, Ser260, Ser271, and Ser282. These residues may serve to limit the, hydrophobicity and facilitate reversible and lipid-selective membrane, binding. The hydrophobic faces of the helices were flanked by a set of, basic amino acid residues on one side and basic amino acid residues, interspersed with glutamates on the other. The disposition of these side, chains gives clues to the basis for the specificities of these peptides, for anionic surfaces.
About this Structure
1PEH is a Single protein structure of sequence from Rattus norvegicus with ACE and NH2 as ligands. Active as Choline-phosphate cytidylyltransferase, with EC number 2.7.7.15 Full crystallographic information is available from OCA.
Reference
Structure of the membrane binding domain of CTP:phosphocholine cytidylyltransferase., Dunne SJ, Cornell RB, Johnson JE, Glover NR, Tracey AS, Biochemistry. 1996 Sep 17;35(37):11975-84. PMID:8810902
Page seeded by OCA on Tue Nov 20 23:44:24 2007
