title: The crystal structure of the Escherichia coli autoinducer-2 processing protein LsrF.
abstract: Many bacteria produce and respond to the quorum sensing signal autoinducer-2 (AI-2). Escherichia coli and Salmonella typhimurium are among the species with the lsr operon, an operon containing AI-2 transport and processing genes that are up regulated in response to AI-2. One of the Lsr proteins, LsrF, has been implicated in processing the phosphorylated form of AI-2. Here, we present the structure of LsrF, unliganded and in complex with two phospho-AI-2 analogues, ribose-5-phosphate and ribulose-5-phosphate. The crystal structure shows that LsrF is a decamer of (alphabeta)(8)-barrels that exhibit a previously unseen N-terminal domain swap and have high structural homology with aldolases that process phosphorylated sugars. Ligand binding sites and key catalytic residues are structurally conserved, strongly implicating LsrF as a class I aldolase.
authors.affiliation: Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, Pennsylvania, United States of America.
authors.forename: Zamia
authors.initials: Z
authors.lastname: Diaz
authors.forename: Karina B
authors.initials: KB
authors.lastname: Xavier
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Miller
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization; D004926:Escherichia coli / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012486:Salmonella typhimurium / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D008024:Ligands; C030654:N-(3-oxohexanoyl)-3-aminodihydro-2(3H)-furanone; D015107:4-Butyrolactone