Involvement of the N-finger in the self-association of GATA-1.
Zinc fingers are recognized as small protein domains that bind to specific DNA sequences. Recently however, zinc fingers from a number of proteins, in particular the GATA family of transcription factors, have also been implicated in specific protein-protein interactions. The erythroid protein GATA-1 contains two zinc fingers: the C-finger, which is sufficient for sequence-specific DNA-binding, and the N-finger, which appears both to modulate DNA-binding and to interact with other transcription factors. We have expressed and purified the N-finger domain and investigated its involvement in the self-association of GATA-1. We demonstrate that this domain does not homodimerize but instead makes intermolecular contacts with the C-finger, suggesting that GATA dimers are maintained by reciprocal N-finger-C-finger contacts. Deletion analysis identifies a 25-residue region, C-terminal to the core N-finger domain, that is sufficient for interaction with intact GATA-1. A similar subdomain exists C-terminal to the C-finger, and we show that self-association is substantially reduced when both subdomains are disrupted by mutation. Moreover, mutations that impair GATA-1 self-association also interfere with its ability to activate transcription in transfection studies.
Mackay
J P
JP
Department of Biochemistry, University of Sydney, Sydney, New South Wales 2006, Australia.
Kowalski
K
K
Fox
A H
AH
Czolij
R
R
King
G F
GF
Crossley
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003035:Cobalt / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D011487:Protein Conformation; D017510:Protein Folding; D013056:Spectrophotometry, Ultraviolet; D014157:Transcription Factors / Q000378:metabolism*; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494689:Gata1 protein, mouse; D009687:Nuclear Proteins; D014157:Transcription Factors; D003035:Cobalt