1fu9
From Proteopedia
SOLUTION STRUCTURE OF THE NINTH ZINC-FINGER DOMAIN OF THE U-SHAPED TRANSCRIPTION FACTOR
Structural highlights
Function[USH_DROME] Transcription regulator that modulates expression mediated by transcription factors of the GATA family such as pnr and srp. Represses transcription of proneural achaete-scute complex (AS-C), which is usually activated by pnr. Involved in cardiogenesis, blood, and eye development. During hematopoiesis, it is required to restrict the number of crystal cells, probably via its interaction with the isoform SrpNC of srp. Negatively regulates expression of sr. Probably acts by interacting with the GATA-type zinc finger of proteins such as pnr and srp, possibly antagonizing the interaction between the GATA-type zinc finger and some cofactor.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedBACKGROUND: Zinc finger domains have traditionally been regarded as sequence-specific DNA binding motifs. However, recent evidence indicates that many zinc fingers mediate specific protein-protein interactions. For instance, several zinc fingers from FOG family proteins have been shown to interact with the N-terminal zinc finger of GATA-1. RESULTS: We have used NMR spectroscopy to determine the first structures of two FOG family zinc fingers that are involved in protein-protein interactions: fingers 1 and 9 from U-shaped. These fingers resemble classical TFIIIA-like zinc fingers, with the exception of an unusual extended portion of the polypeptide backbone prior to the fourth zinc ligand. [15N,(1)H]-HSQC titrations have been used to define the GATA binding surface of USH-F1, and comparison with other FOG family proteins indicates that the recognition mechanism is conserved across species. The surface of FOG-type fingers that interacts with GATA-1 overlaps substantially with the surface through which classical fingers typically recognize DNA. This suggests that these fingers could not contact both GATA and DNA simultaneously. In addition, results from NMR, gel filtration, and sedimentation equilibrium experiments suggest that the interactions are of moderate affinity. CONCLUSIONS: Our results demonstrate unequivocally that zinc fingers comprising the classical betabetaalpha fold are capable of mediating specific contacts between proteins. The existence of this alternative function has implications for the prediction of protein function from sequence data and for the evolution of protein function. Solution structures of two CCHC zinc fingers from the FOG family protein U-shaped that mediate protein-protein interactions.,Liew CK, Kowalski K, Fox AH, Newton A, Sharpe BK, Crossley M, Mackay JP Structure. 2000 Nov 15;8(11):1157-66. PMID:11080638[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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