Exploiting the basis of proline recognition by SH3 and WW domains: design of N-substituted inhibitors.
Src homology 3 (SH3) and WW protein interaction domains bind specific proline-rich sequences. However, instead of recognizing critical prolines on the basis of side chain shape or rigidity, these domains broadly accepted amide N-substituted residues. Proline is apparently specifically selected in vivo, despite low complementarity, because it is the only endogenous N-substituted amino acid. This discriminatory mechanism explains how these domains achieve specific but low-affinity recognition, a property that is necessary for transient signaling interactions. The mechanism can be exploited: screening a series of ligands in which key prolines were replaced by nonnatural N-substituted residues yielded a ligand that selectively bound the Grb2 SH3 domain with 100 times greater affinity.
Nguyen
J T
JT
Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94143, USA.
Turck
C W
CW
Cohen
F E
FE
Zuckermann
R N
RN
Lim
W A
WA
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D051380:GRB2 Adaptor Protein; D015801:Helminth Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism; D011392:Proline / Q000737:chemistry / Q000378:metabolism*; D015202:Protein Engineering; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism; D050737:Proto-Oncogene Proteins c-crk; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D015801:Helminth Proteins; D008024:Ligands; D009842:Oligopeptides; D010750:Phosphoproteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D050737:Proto-Oncogene Proteins c-crk; C085751:Sem-5 protein, C elegans; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins; C088374:YAP1 protein, human; D011392:Proline