Identification of a PU.1-IRF4 protein interaction surface predicted by chemical exchange line broadening.
Relaxation values reflecting residue-specific line broadening revealed amino acids in the DNA-binding domain of PU.1 on a surface potentially involved in protein-protein interactions. Mutation of these amino acids did not cause protein unfolding but destabilized PU.1-DNA binding. Addition of IFN response factor 4 to form the ternary complex recovered binding stability. Fluorescence quenching experiments proved that this surface of PU.1 interacts with IFN response factor 4 during binding. Our results provide evidence that residues that display increased conformational exchange can be used to predict areas of protein-protein interactions.
McKercher
Scott R
SR
The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037-1062, USA.
Lombardo
Christian R
CR
Bobkov
Andrey
A
Jia
Xin
X
Assa-Munt
Nuria
N
D001665:Binding Sites; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry*; D005453:Fluorescence; D050835:Interferon Regulatory Factors; D009154:Mutation; D011487:Protein Conformation; D011518:Proto-Oncogene Proteins / Q000737:chemistry*; D015534:Trans-Activators / Q000737:chemistry*; D014157:Transcription Factors / Q000737:chemistry*; D000099232:Proto-Oncogene Protein Spi-1; D000099218:Interferon Regulatory Factor-4
D004247:DNA; D004268:DNA-Binding Proteins; D050835:Interferon Regulatory Factors; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000099232:Proto-Oncogene Protein Spi-1; D000099218:Interferon Regulatory Factor-4