2hgh: Difference between revisions

[[Image:2hgh.gif|left|200px]]<br /><applet load="2hgh" size="350" color="white" frame="true" align="right" spinBox="true"  

Transcription 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.

2HGH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. The following page contains interesting information on the relation of 2HGH with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb87_1.html Zinc Fingers]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HGH OCA].  

[[Category: Lee, B M.]]

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