title: Induced fit and "lock and key" recognition of 5S RNA by zinc fingers of transcription factor IIIA.
abstract: 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.
authors.affiliation: Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Lee
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Bryan K
authors.initials: BK
authors.lastname: Clarkson
authors.forename: Maria A
authors.initials: MA
authors.lastname: Martinez-Yamout
authors.forename: H Jane
authors.initials: HJ
authors.lastname: Dyson
authors.forename: David A
authors.initials: DA
authors.lastname: Case
authors.forename: Joel M
authors.initials: JM
authors.lastname: Gottesfeld
authors.forename: Peter E
authors.initials: PE
authors.lastname: Wright
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012341:RNA, Ribosomal, 5S / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D035582:Transcription Factor TFIIIA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis; D016335:Zinc Fingers
chemical_list: D046911:Macromolecular Substances; D012341:RNA, Ribosomal, 5S; D035582:Transcription Factor TFIIIA