1UNA

UNASSEMBLED VIRUS COAT PROTEIN DIMER, BACTERIOPHAGE RNA-BINDING DIMER

1UNA の概要

• エントリーDOI: 10.2210/pdb1una/pdb
• 分子名称: GA UNASSEMBLED COAT PROTEIN DIMER (1 entity in total)
• 機能のキーワード: unassembled virus coat protein dimer, bacteriophage, rna-binding dimer, translational repressor, viral protein
• 由来する生物種: Enterobacteria phage GA
• 細胞内の位置: Virion (Potential): P07234
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 27292.73

構造登録者

Ni, C.-Z.,Ely, K.R. (登録日: 1996-04-25, 公開日: 1996-11-08, 最終更新日: 2024-05-22)

主引用文献

Ni, C.Z.,White, C.A.,Mitchell, R.S.,Wickersham, J.,Kodandapani, R.,Peabody, D.S.,Ely, K.R.
Crystal structure of the coat protein from the GA bacteriophage: model of the unassembled dimer.
Protein Sci., 5:2485-2493, 1996

PubMed Abstract: There are four groups of RNA bacteriophages with distinct antigenic and physicochemical properties due to differences in surface residues of the viral coat proteins. Coat proteins also play a role as translational repressor during the viral life cycle, binding an RNA hairpin within the genome. In this study, the first crystal structure of the coat protein from a Group II phage GA is reported and compared to the Group I MS2 coat protein. The structure of the GA dimer was determined at 2.8 A resolution (R-factor = 0.20). The overall folding pattern of the coat protein is similar to the Group I MS2 coat protein in the intact virus (Golmohammadi R, Valegård K, Fridborg K, Liljas L. 1993, J Mol Biol 234:620-639) or as an unassembled dimer (Ni Cz, Syed R, Kodandapani R. Wickersham J, Peabody DS, Ely KR, 1995, Structure 3:255-263). The structures differ in the FG loops and in the first turn of the alpha A helix. GA and MS2 coat proteins differ in sequence at 49 of 129 amino acid residues. Sequence differences that contribute to distinct immunological and physical properties of the proteins are found at the surface of the intact virus in the AB and FG loops. There are six differences in potential RNA contact residues within the RNA-binding site located in an antiparallel beta-sheet across the dimer interface. Three differences involve residues in the center of this concave site: Lys/Arg 83, Ser/Asn 87, and Asp/Glu 89. Residue 87 was shown by molecular genetics to define RNA-binding specificity by GA or MS2 coat protein (Lim F. Spingola M, Peabody DS, 1994, J Biol Chem 269:9006-9010). This sequence difference reflects recognition of the nucleotide at position -5 in the unpaired loop of the translational operators bound by these coat proteins. In GA, the nucleotide at this position is a purine whereas in MS2, it is a pyrimidine.

PubMed: 8976557

実験手法

X-RAY DIFFRACTION (2.8 Å)