Multiple binding modes of an N‐terminal CCR5‐peptide in complex with HIV‐1 gp120. (28th December 2021)

• Record Type: Journal Article
• Authors: Moseri, Adi; Akabayov, Sabine R.; Cohen, Leah S.; Naider, Fred; Anglister, Jacob
• Is Part Of: FEBS journal. Volume 289:Number 11(2022)
• Page Start: 3132
• Page End: 3147
• Publication Date: 2021-12-28
• Subjects: CCR5 -- HIV‐1 envelope protein -- intermolecular interactions -- sulphated tyrosine -- TRNOE; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.16328
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : The N‐terminal segment of CCR5 contains four tyrosine residues, sulphation of two of which is essential for high‐affinity binding to gp120. In the present study, the interactions of gp120YU2 with a 27‐residue N‐terminal CCR5 peptide sulphated at position Y10 and Y14, i.e. Nt‐CCR5, were studied using 13 C‐edited‐HMQC methyl‐NOESY [ 1 H( 13 C)‐ 1 H], combined with transferred NOE NMR spectroscopy. A large number of pairwise interactions were observed between the methyl protons of methionine, threonine, valine and isoleucine residues of gp120, and the aromatic tyrosine‐protons of Nt‐CCR5. M434, V120 and V200 of gp120 were found to interact with all four tyrosine residues, Y3, sY10, sY14 and Y15. Particularly intriguing was the observation that Y3 and Y15 interact with the same gp120 methyl protons. Such interactions cannot be explained by the single cryo‐EM structure of gp120/CD4/CCR5 complex published recently (Nature, 565, 318–323, 2019). Rather, they are consistent with the existence of a dynamic equilibrium involving two or more binding modes of Nt‐CCR5 to gp120. These different modes of binding can coexist because the surface of gp120 contains two sites that can optimally interact with a sulphated tyrosine residue and two sites that can interact favorably with a non‐sulphated tyrosine residue. Modelling of gp120YU2 complexed with the Nt‐CCR5 peptide or with the entire CCR5 receptor provides an explanation for the NMR observations and the existence of these different binding modes of the disordered N‐terminus of CCR5. The data presented extend our understanding of the two‐step model and suggest a more variable binding mode of Nt‐CCR5 with gp120. Abstract : The N‐terminal segment of CCR5, Nt‐CCR5 contains four tyrosine residues, sulfation of two of which is essential for high‐affinity binding to HIV‐1 gp120. A large number of interactions were observed using TRNOE NMR measurements between the methyl protons of the gp120 co‐receptor binding site and the tyrosine‐protons of Nt‐CCR5. Such interactions are consistent with the existence of a dynamic equilibrium involving two or more binding modes of Nt‐CCR5 to gp120.