Mutating P2 and P1 residues at cleavage junctions in the HIV‐1 pol polyprotein Effects on hydrolysis by HIV‐1 proteinase

FEBS Letters

Phylip, Lowri H.¹  Le Grice, Stuart F.J.²  Jupp, Ray A.¹  Kay, John¹  Mills, John S.³ 

[1] Department of Biochemistry, University of Wales College of Cardiff, P.O. Box 903, Cardiff, CF1 1ST, UK;Division of Infectious Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA;Roche Products Ltd., P.O. Box 8, Welwyn Garden City, Herts AL7 3AY, UK

关键词: HIV-1 proteinase;    Specificity;    Polyprotein processing;    Cleavage site mutagenesis;    PR;    proteinase;    RT;    reverse transcriptase;    IN;    integrase. The nomenclature system of Schechter and Berger [19] i.e. P2-P1*P1′-P2′ is used to depict amino acids adjacent to the residues in the P1 and P1′ positions which contribute the scissile peptide bond (indicated by an asterisk*);   

DOI  :  10.1016/0014-5793(91)80583-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Mutations were introduced into the P₂ and P₁ positions of the junctions, (a) linking reverse transcriptase (RT) and integrase (IN) (-Leu*Phe-) and (b) between the p51 and RNase H domain (-Phe*Tyr-) within p66 of RT in the HIV-1 pol polyprotein. Processing by HIV proteinase (PR) in cis was monitored upon expression of these constructs in E. coli. Whereas the presence of Leu or Phe in P₁ permitted rapid cleavage at either junction, substitution of a β-branched (He) hydrophobic residue essentially abolished hydrolysis. By contrast, placement of a β-branched (Val) residue in the P₁ position flanking such -Hydrophobic*Hydrophobic- junctions resulted in effective cleavage of the scissile peptide bond. Gly in P₂, however, abrogated cleavage. The significance of these findings in terms of PR specificity, polyprotein processing and the generation of homodimeric (p51/p51) RT for crystallisation purposes is discussed.

【 授权许可】

Unknown