3BRJ

Crystal structure of mannitol operon repressor (MtlR) from Vibrio parahaemolyticus RIMD 2210633

Summary for 3BRJ

• Entry DOI: 10.2210/pdb3brj/pdb
• Descriptor: Mannitol operon repressor, 1,2-ETHANEDIOL, GLYCEROL, ... (4 entities in total)
• Functional Keywords: apc85967.1, mannitol operon repressor, mtlr, vibrio parahaemolyticus rimd 2210633, structural genomics, psi-2, protein structure initiative, midwest center for structural genomics, mcsg, transcription
• Biological source: Vibrio parahaemolyticus RIMD 2210633
• Total number of polymer chains: 4
• Total formula weight: 79692.69

Authors

Tan, K.,Zhou, M.,Moy, S.,Joachimiak, A.,Midwest Center for Structural Genomics (MCSG) (deposition date: 2007-12-21, release date: 2008-01-15, Last modification date: 2024-10-30)

Primary citation

Tan, K.,Clancy, S.,Borovilos, M.,Zhou, M.,Horer, S.,Moy, S.,Volkart, L.L.,Sassoon, J.,Baumann, U.,Joachimiak, A.
The mannitol operon repressor MtlR belongs to a new class of transcription regulators in bacteria.
J.Biol.Chem., 284:36670-36679, 2009

PubMed Abstract: Many bacteria express phosphoenolpyruvate-dependent phosphotransferase systems (PTS). The mannitol-specific PTS catalyze the uptake and phosphorylation of d-mannitol. The uptake system comprises several genes encoded in the single operon. The expression of the mannitol operon is regulated by a proposed transcriptional factor, mannitol operon repressor (MtlR) that was first studied in Escherichia coli. Here we report the first crystal structures of MtlR from Vibrio parahemeolyticus (Vp-MtlR) and its homolog YggD protein from Shigella flexneri (Sf-YggD). MtlR and YggD belong to the same protein family (Pfam05068). Although Vp-MtlR and Sf-YggD share low sequence identity (22%), their overall structures are very similar, representing a novel all alpha-helical fold, and indicate similar function. However, their lack of any known DNA-binding structural motifs and their unfavorable electrostatic properties imply that MtlR/YggD are unlikely to bind a specific DNA operator directly as proposed earlier. This structural observation is further corroborated by in vitro DNA-binding studies of E. coli MtlR (Ec-MtlR), which detected no interaction of Ec-MtlR with the well characterized mannitol operator/promoter region. Therefore, MtlR/YggD belongs to a new class of transcription factors in bacteria that may regulate gene expression indirectly as a part of a larger transcriptional complex.

PubMed: 19840941
DOI: 10.1074/jbc.M109.062679

Experimental method

X-RAY DIFFRACTION (2.75 Å)