7ofz

Nontypeable Haemophillus influenzae SapA in complex with double stranded RNA

spinqualitylabelsall models 7ofz, resolution 2.62Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7ofz is a 2 chain structure with sequence from Escherichia coli and Haemophilus influenzae 86-028NP. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.62Å Ligands: NA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q4QL73_HAEI8 Publication Abstract from PubMed Nontypeable Haemophilus influenzae (NTHi) is a significant pathogen in respiratory disease and otitis media. Important for NTHi survival, colonization and persistence in vivo is the Sap (sensitivity to antimicrobial peptides) ABC transporter system. Current models propose a direct role for Sap in heme and antimicrobial peptide (AMP) transport. Here, the crystal structure of SapA, the periplasmic component of Sap, in a closed, ligand bound conformation, is presented. Phylogenetic and cavity volume analysis predicts that the small, hydrophobic SapA central ligand binding cavity is most likely occupied by a hydrophobic di- or tri- peptide. The cavity is of insufficient volume to accommodate heme or folded AMPs. Crystal structures of SapA have identified surface interactions with heme and dsRNA. Heme binds SapA weakly (Kd 282 muM) through a surface exposed histidine, while the dsRNA is coordinated via residues which constitute part of a conserved motif (estimated Kd 4.4 muM). The RNA affinity falls within the range observed for characterized RNA/protein complexes. Overall, we describe in molecular-detail the interactions of SapA with heme and dsRNA and propose a role for SapA in the transport of di- or tri-peptides. The structure of nontypeable Haemophilus influenzae SapA in a closed conformation reveals a constricted ligand-binding cavity and a novel RNA binding motif.,Lukacik P, Owen CD, Harris G, Bolla JR, Picaud S, Alibay I, Nettleship JE, Bird LE, Owens RJ, Biggin PC, Filippakopoulos P, Robinson CV, Walsh MA PLoS One. 2021 Oct 15;16(10):e0256070. doi: 10.1371/journal.pone.0256070. , eCollection 2021. PMID:34653190 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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