1jcc
From Proteopedia
Crystal Structure of a Novel Alanine-Zipper Trimer at 1.7 A Resolution, V13A,L16A,V20A,L23A,V27A,M30A,V34A mutations
Structural highlights
FunctionLPP_ECOLI Interacts with the peptidoglycan both covalently and noncovalently. This interaction contributes to the maintenance of the structural and functional integrity of the cell envelope. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedSpecific sequence signals at alpha-helix termini can assist protein folding by punctuating and cueing secondary structural elements in the final native conformation. Here we report the crystallization of a 56-residue alanine-containing peptide, denoted Ala-10(56), in the presence of Zn(2+). The 1.7 A crystal structure shows that Ala-10(56) forms a parallel trimeric coiled coil with three zinc ions anchoring distinct capping conformations at the amino-terminal ends of the three helices. In each polypeptide chain, the free alpha-amino nitrogen and carbonyl oxygen of the amino-terminal Ser residue coordinate to a Zn(2+) ion to form a five-membered chelate, and the syn-unidentate interaction of the Asp7 side chain with the Zn(2+) cation leads to the formation of a unique docking arrangement for helix capping. Moreover, the coordination of the zinc ion involves a neighboring trimer molecule in the crystal. Consequently, the crystal contacts are stabilized by carboxylate-Zn(2+) interactions between four Ala-10(56) trimers in the crystal lattice. The observed synergy between the protein-zinc ion recognition and the helix-packing arrangements would contribute to the conformational specificity of the Ala-10(56) trimer. Zinc-mediated helix capping in a triple-helical protein.,Liu J, Dai J, Lu M Biochemistry. 2003 May 20;42(19):5657-64. PMID:12741822[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Escherichia coli | Large Structures | Dai J | Liu J | Lu M