PDBsum entry 2w25

Transcription

PDB id: 2w25

Contents

Protein chains

147 a.a. *

Waters ×72

* Residue conservation analysis

PDB id:

2w25

Name:

Transcription

Title:

Crystal structure of glu104ala mutant

Structure:

Probable transcriptional regulatory protein. Chain: a, b. Synonym: leucine-responsive regulatory protein, rv3291c. Engineered: yes. Mutation: yes

Source:

Mycobacterium tuberculosis. Organism_taxid: 83332. Strain: h37rv. Expressed in: escherichia coli. Expression_system_taxid: 511693.

Resolution:

2.15Å R-factor: 0.217 R-free: 0.218

Authors:

T.Shrivastava,R.Ramachandran

Key ref:

T.Shrivastava et al. (2009). Ligand-induced structural transitions, mutational analysis, and 'open' quaternary structure of the M. tuberculosis feast/famine regulatory protein (Rv3291c). J Mol Biol, 392, 1007-1019. PubMed id: 19651141 DOI: 10.1016/j.jmb.2009.07.084

Date:

24-Oct-08 Release date: 17-Nov-09

Protein chains

P96896  (P96896_MYCTO) -  Leucine-responsive regulatory protein from Mycobacterium tuberculosis (strain CDC 1551 / Oshkosh)

Seq: 150 a.a.

Struc: 147 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1016/j.jmb.2009.07.084

J Mol Biol 392:1007-1019 (2009)

PubMed id: 19651141

Ligand-induced structural transitions, mutational analysis, and 'open' quaternary structure of the M. tuberculosis feast/famine regulatory protein (Rv3291c).

T.Shrivastava, A.Dey, R.Ramachandran.

ABSTRACT

Rv3291c is a member of the feast/famine regulatory protein family that is known to form stable protein-DNA complexes. We report a specific oligomeric transition between hexadecameric and octameric/lower-order oligomers in the presence of Phe that supports an effector-mediated model for the disassembly of a nucleosome-like particle. We had generated two mutants, Gly102Thr and Glu104Ala, which are part of the essential 100-106 effector-binding loop. The Gly102Thr mutant adopts an unusual 'open' quaternary structure and offers interesting functional insights co-related to the binding of an effector. This is similar to the previously reported Escherichia coli Lrp co-crystallized in the presence of DNA where the interactions of the substrate with the N-terminal DNA binding domain presumably lead to symmetry deviations to the oligomeric association. The present structure represents a direct evidence to support that changes made to the effector-binding domain at the C-terminus also result in a functionally relevant quaternary structural change. Conversely, the Glu104Ala mutant retains the closed quaternary association observed in the native protein and reveals nonsymmetrical interaction effects in the two subunits of the dimer. We also report that the native protein unexpectedly binds Lys but does not recognize Arg and offer a structural explanation for it. Error-scaled difference distance matrix analysis suggests that the protein has a relatively flexible core that is presumably needed to mediate the structural changes necessary for the protein's regulatory functions.

Selected figure(s)

Figure 3.
Fig. 3. Quaternary associations from the crystal structures. (a) Gly102Thr, (b) Glu104Ala, and (c) E. coli Lrp (PDB ID: 2GQQ).

Figure 6.
Fig. 6. Interactions of Lys in its complex with MtbLrp. The protein is shown in cartoon representation. Hydrogen bonds are indicated by broken lines. Selected binding site residues are labeled and plotted in stick representation. Red spheres indicate water molecules.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2009, 392, 1007-1019) copyright 2009.

Figures were selected by the author.