title: Crystal structure of the AAA+ alpha domain of E. coli Lon protease at 1.9A resolution.
abstract: The crystal structure of the small, mostly helical alpha domain of the AAA+ module of the Escherichia coli ATP-dependent protease Lon has been solved by single isomorphous replacement combined with anomalous scattering and refined at 1.9A resolution to a crystallographic R factor of 17.9%. This domain, comprising residues 491-584, was obtained by chymotrypsin digestion of the recombinant full-length protease. The alpha domain of Lon contains four alpha helices and two parallel strands and resembles similar domains found in a variety of ATPases and helicases, including the oligomeric proteases HslVU and ClpAP. The highly conserved "sensor-2" Arg residue is located at the beginning of the third helix. Detailed comparison with the structures of 11 similar domains established the putative location of the nucleotide-binding site in this first fragment of Lon for which a crystal structure has become available.
authors.affiliation: Macromolecular Crystallography Laboratory, National Cancer Institute at Frederick, MCL Bldg. 536, Rm. 5, Frederick, MD 21702-1201, USA.
authors.forename: Istvan
authors.initials: I
authors.lastname: Botos
authors.forename: Edward E
authors.initials: EE
authors.lastname: Melnikov
authors.forename: Scott
authors.initials: S
authors.lastname: Cherry
authors.forename: Anna G
authors.initials: AG
authors.lastname: Khalatova
authors.forename: Fatima S
authors.initials: FS
authors.lastname: Rasulova
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Tropea
authors.forename: Michael R
authors.initials: MR
authors.lastname: Maurizi
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Rotanova
authors.forename: Alla
authors.initials: A
authors.lastname: Gustchina
authors.forename: Alexander
authors.initials: A
authors.lastname: Wlodawer
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry; D001120:Arginine; D018360:Crystallography, X-Ray / Q000379:methods; D029968:Escherichia coli Proteins / Q000737:chemistry*; D015394:Molecular Structure; D010446:Peptide Fragments / Q000737:chemistry; D049070:Protease La / Q000737:chemistry*; D017434:Protein Structure, Tertiary
chemical_list: D029968:Escherichia coli Proteins; D010446:Peptide Fragments; D001120:Arginine; C483567:Lon protein, E coli; D049070:Protease La; D000251:Adenosine Triphosphatases