| Literature DB >> 12011453 |
Michael J Romanowski1, Raymond E Soccio, Jan L Breslow, Stephen K Burley.
Abstract
The x-ray structure of the mouse cholesterol-regulated START protein 4 (StarD4) has been determined at 2.2-A resolution, revealing a compact alpha/beta structure related to the START domain present in the cytoplasmic C-terminal portion of human MLN64. The volume of the putative lipid-binding tunnel was estimated at 847 A(3), which is consistent with the binding of one cholesterol-size lipid molecule. Comparison of the tunnel-lining residues in StarD4 and MLN64-START permitted identification of possible lipid specificity determinants in both molecular tunnels. Homology modeling of related proteins, and comparison of the StarD4 and MLN64-START structures, showed that StarD4 is a member of a large START domain superfamily characterized by the helix-grip fold. Additional mechanistic and evolutionary studies should be facilitated by the availability of a second START domain structure from a distant relative of MLN64.Entities:
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Year: 2002 PMID: 12011453 PMCID: PMC124509 DOI: 10.1073/pnas.052140699
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205