1CW6

REFINED SOLUTION STRUCTURE OF LEUCOCIN A

1CW6 の概要

• エントリーDOI: 10.2210/pdb1cw6/pdb
• 関連するPDBエントリー: 2LEU
• NMR情報: BMRB: 4507
• 分子名称: TYPE IIA BACTERIOCIN LEUCOCIN A (1 entity in total)
• 機能のキーワード: antimicrobial peptide, bacteriocin, toxin
• 由来する生物種: Leuconostoc gelidum
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3937.32

構造登録者

Wang, Y.,Henz, M.E.,Gallagher, N.L.F.,Chai, S.,Yan, L.Z.,Gibbs, A.C.,Stiles, M.E.,Wishart, D.S.,Vederas, J.C. (登録日: 1999-08-25, 公開日: 1999-09-08, 最終更新日: 2022-02-16)

主引用文献

Wang, Y.,Henz, M.E.,Gallagher, N.L.,Chai, S.,Gibbs, A.C.,Yan, L.Z.,Stiles, M.E.,Wishart, D.S.,Vederas, J.C.
Solution structure of carnobacteriocin B2 and implications for structure-activity relationships among type IIa bacteriocins from lactic acid bacteria.
Biochemistry, 38:15438-15447, 1999

PubMed Abstract: Carnobacteriocin B2 (CbnB2), a type IIa bacteriocin, is a 48 residue antimicrobial peptide from the lactic acid bacterium Carnobacterium pisicola LV17B. Type IIa bacteriocins have a conserved YGNGVXC sequence near the N-terminus and usually contain a disulfide bridge. CbnB2 seemed to be unique in that its two cysteines (Cys9 and Cys14) could be isolated as free thiols [Quadri et al. (1994) J. Biol. Chem. 26, 12204-12211]. To establish the structural consequences of the presence or absence of a disulfide bridge and to investigate if the YGNGVXC sequence is a receptor-binding motif [Fleury et al. (1996) J. Biol. Chem. 271, 14421-14429], the three-dimensional solution structure of CbnB2 was determined by two-dimensional (1)H nuclear magnetic resonance (NMR) techniques. Mass spectroscopic and thiol modification experiments on CbnB2 and on model peptides, in conjunction with activity measurements, were used to verify the redox status of CbnB2. The results show that CbnB2 readily forms a disulfide bond and that this peptide has full antimicrobial activity. NMR results indicate that CbnB2 in trifluoroethanol (TFE) has a well-defined central helical structure (residues 18-39) but a disordered N terminus. Comparison of the CbnB2 structure with the refined solution structure of leucocin A (LeuA), another type IIa bacteriocin, indicates that the central helical structure is conserved between the two peptides despite differences in sequence but that the N-terminal structure (a proposed receptor binding site) is not. This is unexpected because LeuA and CbnB2 exhibit >66% sequence identity in the first 24 residues. This suggests that the N-terminus, which had been proposed [Fleury et al. (1996) J. Biol. Chem. 271, 14421-14429] to be a receptor binding site of type IIa bacteriocins, may not be directly involved and that recognition of the amphiphilic helical portion is the critical feature.

PubMed: 10569926
DOI: 10.1021/bi991351x

実験手法

SOLUTION NMR