Table 2.
Sequence specificity of the interaction of the RIM PDZ domains with the C-terminal 9 residues of ERC1b
| Sequence | Position of mutant | RIM1 PDZ domain | RIM2 PDZ domain |
|---|---|---|---|
| ERC1b | NA | ++ | ++ |
| QDEEEGIWA* | WT | ++ | + |
| QDEEEGIWD* | 0 | − | − |
| QDEEEGIWL* | 0 | + | − |
| QDEEEGIDA* | −1 | − | − |
| QDEEEGIAA* | −1 | − | − |
| QDEEEGDWA* | −2 | − | − |
| QDEEEGAWA* | −2 | − | − |
| QDEEEDIWA* | −3 | − | − |
| QDEEEAIWA* | −3 | − | − |
| QDEEKGIWA* | −4 | ++ | + |
| QDEEAGIWA* | −4 | ++ | + |
| QDEKEGIWA* | −5 | ++ | + |
| QDEAEGIWA* | −5 | ++ | + |
Interactions were measured by yeast two-hybrid by using survival on selection plates and β-galactosidase activation as criteria. The RIM PDZ domains were supplied as bait vectors in pLexN, and the C-terminal sequences of ERC1b as prey vectors in pVP16 containing either the C-terminal half of ERC1b or only the nine residues shown. Interactions were scored as strong (++), moderate (+), and absent (−), depending on the relative strength of color development and survival of colonies. Asterisk denotes a stop codon. NA, not applicable.