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Publication Abstract from PubMed

UCS proteins, such as UNC-45, influence muscle contraction and other myosin-dependent motile processes. We report the first X-ray crystal structure of a UCS domain-containing protein, the UNC-45 myosin chaperone from Drosophila melanogaster (DmUNC-45). The structure reveals that the central and UCS domains form a contiguous arrangement of 17 consecutive helical layers that arrange themselves into five discrete armadillo repeat subdomains. Small-angle X-ray scattering data suggest that free DmUNC-45 adopts an elongated conformation and exhibits flexibility in solution. Protease sensitivity maps to a conserved loop that contacts the most carboxy-terminal UNC-45 armadillo repeat subdomain. Amino acid conservation across diverse UCS proteins maps to one face of this carboxy-terminal subdomain, and the majority of mutations that affect myosin-dependent cellular activities lie within or around this region. Our crystallographic, biophysical, and biochemical analyses suggest that DmUNC-45 function is afforded by its flexibility and by structural integrity of its UCS domain.

X-ray Crystal Structure of the UCS Domain-Containing UNC-45 Myosin Chaperone from Drosophila melanogaster.,Lee CF, Hauenstein AV, Fleming JK, Gasper WC, Engelke V, Sankaran B, Bernstein SI, Huxford T Structure. 2011 Mar 9;19(3):397-408. PMID:21397190^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.