1l1c

From Proteopedia

Revision as of 18:02, 20 November 2007

Structure of the LicT Bacterial Antiterminator Protein in Complex with its RNA Target

Overview

LicT is a bacterial regulatory protein able to prevent the premature, arrest of transcription. When activated, LicT binds to a 29 base RNA, hairpin overlapping a terminator located in the 5' mRNA leader region of, the target genes. We have determined the solution structure of the LicT, RNA-binding domain (CAT) in complex with its ribonucleic antiterminator, (RAT) target by NMR spectroscopy (PDB 1L1C). CAT is a beta-stranded, homodimer that undergoes no important conformational changes upon complex, formation. It interacts, through mostly hydrophobic and stacking, interactions, with the distorted minor groove of the hairpin stem that is, interrupted by two asymmetric internal loops. Although different in, sequence, these loops share sufficient structural analogy to be recognized, similarly by symmetry-related elements of the protein dimer, leading to a, quasi- symmetric structure reminiscent of that observed with dimeric, transcription regulators bound to palindromic DNA. Sequence analysis, suggests that this RNA- binding mode, where the RAT strands are clamped by, the CAT dimer, is conserved in homologous systems.

About this Structure

1L1C is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.

Reference

Solution structure of the LicT-RNA antitermination complex: CAT clamping RAT., Yang Y, Declerck N, Manival X, Aymerich S, Kochoyan M, EMBO J. 2002 Apr 15;21(8):1987-97. PMID:11953318

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