5deq

Crystal structure of transcriptional factor AraR from Bacteroides thetaiotaomicron VPI in complex with L-arabinoseCrystal structure of transcriptional factor AraR from Bacteroides thetaiotaomicron VPI in complex with L-arabinose

Structural highlights 5deq is a 2 chain structure with sequence from Bacteroides thetaiotaomicron VPI-5482. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.95Å Ligands: , , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q8AAV8_BACTN Publication Abstract from PubMed Carbohydrate metabolism plays a crucial role in the ecophysiology of human gut microbiota. Mechanisms of transcriptional regulation of sugar catabolism in commensal and prevalent human gut bacteria such as Bacteroides thetaiotaomicron remain mostly unknown. By a combination of bioinformatics and experimental approaches, we have identified an NrtR family transcription factor (BT0354 in B. thetaiotaomicron, BtAraR) as a novel regulator controlling the arabinose utilization genes. L-arabinose was confirmed to be a negative effector of BtAraR. We have solved the crystal structures of the apo and L-arabinose-bound BtAraR proteins, as well as the complex of apo-protein with a specific DNA operator. BtAraR forms a homodimer with each subunit comprised of the ligand-binding Nudix hydrolase-like domain and the DNA-binding winged-helix-turn-helix (wHTH) domain. We have identified the residues involved in binding of L-arabinose and recognition of DNA. The majority of these residues are well conserved in the AraR orthologs in Bacteroidetes. In the structure of the BtAraR-DNA complex, we found the unique interaction of arginine intercalating its guanidinum moiety into the base pair stacking of B-DNA. L-arabinose binding induces movement of wHTH domains, resulting in a conformation unsuitable for DNA binding. Our analysis facilitates reconstruction of the metabolic and regulatory networks involved in carbohydrate utilization in human gut Bacteroides. A novel transcriptional regulator of L-arabinose utilization in human gut bacteria.,Chang C, Tesar C, Li X, Kim Y, Rodionov DA, Joachimiak A Nucleic Acids Res. 2015 Oct 4. pii: gkv1005. PMID:26438537 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Transcriptional activator 3D structures

spinqualitylabelsall models 5deq, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image