1JCC

Crystal Structure of a Novel Alanine-Zipper Trimer at 1.7 A Resolution, V13A,L16A,V20A,L23A,V27A,M30A,V34A mutations

Summary for 1JCC

• Entry DOI: 10.2210/pdb1jcc/pdb
• Related: 1EQ7 1JCB 1JCD
• Descriptor: MAJOR OUTER MEMBRANE LIPOPROTEIN, ZINC ION (3 entities in total)
• Functional Keywords: lipoprotein, protein folding, coiled coil, helix capping, alanine-zipper, membrane protein
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane ; Lipid-anchor : P69776
• Total number of polymer chains: 3
• Total formula weight: 17911.93

Authors

Liu, J.,Dai, J.,Lu, M. (deposition date: 2001-06-08, release date: 2003-06-17, Last modification date: 2023-08-16)

Primary citation

Liu, J.,Dai, J.,Lu, M.
Zinc-Mediated Helix Capping in A Triple-Helical Protein
Biochemistry, 42:5657-5664, 2003

PubMed Abstract: Specific 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.

PubMed: 12741822
DOI: 10.1021/bi026828a

Experimental method

X-RAY DIFFRACTION (1.7 Å)