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- Document 0661
- DOCN M9620661
- TI A single amino acid in the SH3 domain of Hck determines its high
- affinity and specificity in binding to HIV-1 Nef protein.
- DT 9602
- AU Lee CH; Leung B; Lemmon MA; Zheng J; Cowburn D; Kuriyan J; Saksela K;
- Laboratory of Molecular Biophysics, Rockefeller University, New; York,
- NY 10021, USA.
- SO EMBO J. 1995 Oct 16;14(20):5006-15. Unique Identifier : AIDSLINE
- MED/96067129
- AB We have examined the differential binding of Hck and Fyn to HIV-1 Nef to
- elucidate the structural basis of SH3 binding affinity and specificity.
- Full-length Nef bound to Hck SH3 with the highest affinity reported for
- an SH3-mediated interaction (KD 250 nM). In contrast to Hck, affinity of
- the highly homologous Fyn SH3 for Nef was too weak (KD > 20 microM) to
- be accurately determined. We show that this distinct specificity lies in
- a variable loop, the 'RT loop', positioned close to conserved SH3
- residues implicated in the binding of proline-rich (PxxP) motifs. A
- mutant Fyn SH3 with a single amino acid substitution (R96I) in its RT
- loop had an affinity (KD 380 nM) for Nef comparable with that of Hck
- SH3. Based on additional mutagenesis studies we propose that the
- selective recognition of Nef by Hck SH3 is determined by hydrophobic
- interactions involving an isoleucine residue in its RT loop. Although
- Nef contains a PxxP motif which is necessary for the interaction with
- Hck SH3, high affinity binding was only observed for intact Nef protein.
- The binding of a peptide containing the Nef PxxP motif showed > 300-fold
- weaker affinity for Hck SH3 than full-length Nef.
- DE *src Homology Domains Amino Acid Sequence Biosensors Calorimetry
- Circular Dichroism Comparative Study Gene Products,
- nef/GENETICS/*METABOLISM HIV-1/GENETICS/*METABOLISM Models, Molecular
- Molecular Sequence Data Oligopeptides/CHEMICAL SYNTHESIS Precipitation
- Protein Binding Protein Conformation Protein-Tyrosine
- Kinase/GENETICS/*METABOLISM Proto-Oncogene
- Proteins/GENETICS/*METABOLISM Recombinant Proteins/METABOLISM Sequence
- Homology, Amino Acid Spectrometry, Fluorescence Structure-Activity
- Relationship Support, Non-U.S. Gov't Support, U.S. Gov't, P.H.S. Time
- Factors JOURNAL ARTICLE
-
- SOURCE: National Library of Medicine. NOTICE: This material may be
- protected by Copyright Law (Title 17, U.S.Code).
-
-