2hgh
From Proteopedia
Transcription Factor IIIA zinc fingers 4-6 bound to 5S rRNA 55mer (NMR structure)
Structural highlights
FunctionTF3A_XENLA Acts as both a positive transcription factor for 5S RNA genes and a specific RNA binding protein that complexes with 5S RNA in oocytes to form the 7S ribonucleoprotein storage particle. May play an essential role in the developmental change in 5S RNA gene expression. Interacts with the internal control region (ICR) of approximately 50 bases within the 5S RNA genes, is required for correct transcription of these genes by RNA polymerase III. Also binds the transcribed 5S RNA's. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTranscription factor IIIA (TFIIIA) is a Cys2His2 zinc finger protein that regulates expression of the 5 S ribosomal RNA gene by binding specifically to the internal control element. TFIIIA also functions in transport and storage of 5 S RNA by binding directly to the RNA transcript. To obtain insights into the mechanism by which TFIIIA recognizes 5 S RNA, we determined the solution structure of the middle three zinc fingers bound to the central core of 5 S RNA. Finger 4 utilizes "lock and key" recognition to bind in the widened major groove of the pre-structured RNA loop E motif. This interaction is mediated by direct hydrogen bonding interactions with bases. In contrast, recognition of loop A, a flexible junction of three helices, occurs by an induced fit mechanism that involves reorganization of the conserved CAUA motif and structuring of the finger 5-finger 6 interface to form a complementary RNA binding surface. Induced fit and "lock and key" recognition of 5S RNA by zinc fingers of transcription factor IIIA.,Lee BM, Xu J, Clarkson BK, Martinez-Yamout MA, Dyson HJ, Case DA, Gottesfeld JM, Wright PE J Mol Biol. 2006 Mar 17;357(1):275-91. Epub 2005 Dec 20. PMID:16405997[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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