1mv4

TM9A251-284: A Peptide Model of the C-Terminus of a Rat Striated Alpha Tropomyosin

spinqualitylabelsall models 1mv4, 10 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1mv4 is a 2 chain structure with sequence from Rattus norvegicus. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1ihq, 1tmz, 1ic2 Gene: TPM1 (Rattus norvegicus) Resources: FirstGlance, OCA, RCSB, PDBsum Function [TPM1_RAT] Binds to actin filaments in muscle and non-muscle cells. Plays a central role, in association with the troponin complex, in the calcium dependent regulation of vertebrate striated muscle contraction. Smooth muscle contraction is regulated by interaction with caldesmon. In non-muscle cells is implicated in stabilizing cytoskeleton actin filaments. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Coiled coils are well-known as oligomerization domains, but they are also important sites of protein-protein interactions. We determined the NMR solution structure and backbone (15)N relaxation rates of a disulfide cross-linked, two-chain, 37-residue polypeptide containing the 34 C-terminal residues of striated muscle alpha-tropomyosin, TM9a(251-284). The peptide binds to the N-terminal region of TM and to the tropomyosin-binding domain of the regulatory protein, troponin T. Comparison of the NMR solution structure of TM9a(251-284) with the X-ray structure of a related peptide [Li, Y., Mui, S., Brown, J. H., Strand, J., Reshetnikova, L., Tobacman, L. S., and Cohen, C. (2002) Proc. Natl. Acad. Sci. U.S.A. 99, 7378-7383] reveals significant differences. In solution, residues 253-269 (like most of the tropomyosin molecule) form a canonical coiled coil. Residues 270-279, however, are parallel, linear helices, novel for tropomyosin. The packing between the parallel helices results from unusual interface residues that are atypical for coiled coils. Y267 has poor packing at the coiled-coil interface and a lower R(2) relaxation rate than neighboring residues, suggesting there is conformational flexibility around this residue. The last five residues are nonhelical and flexible. The exposed surface presented by the parallel helices, and the flexibility around Y267 and the ends, may facilitate binding to troponin T and formation of complexes with the N-terminus of tropomyosin and actin. We propose that unusual packing and flexibility are general features of coiled-coil domains in proteins that are involved in intermolecular interactions. The structure of the carboxyl terminus of striated alpha-tropomyosin in solution reveals an unusual parallel arrangement of interacting alpha-helices.,Greenfield NJ, Swapna GV, Huang Y, Palm T, Graboski S, Montelione GT, Hitchcock-DeGregori SE Biochemistry. 2003 Jan 28;42(3):614-9. PMID:12534273 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tropomyosin

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