Crystallographic analysis of bacterial signal peptidase in ternary complex with arylomycin A2 and a beta-sultam inhibitor.
Bacterial type I signal peptidase (SPase I), an essential membrane-bound endopeptidase with a unique Ser/Lys dyad mechanism, is being investigated as a potential novel antibiotic target. We present here binding and inhibition assays along with crystallographic data that shows that the lipohexapeptide-based natural product arylomycin A2 and the morpholino-beta-sultam derivative (BAL0019193) inhibit SPase I by binding to non-overlapping subsites near the catalytic center. The 2.0 A resolution crystal structure of the soluble catalytic domain of Escherichia coli SPase I (SPase I Delta2-75) in ternary complex with arylomycin A2 and BAL0019193 reveals the position of BAL0019193 adjacent to arylomycin A2 within the SPase I binding site. BAL0019193 binds in a noncovalent manner in close proximity to SPase I residues Ser88, Ser90, Lys145, Asn277, Ala279, and Glu307, as well as atom O45 of arylomycin A2. The binding mode of arylomycin A2 in this 2.0 A resolution ternary complex is compared to that seen in the previous 2.5 A resolution arylomycin A2-SPase cocrystal structure. This work contributes to our understanding of SPase I inhibitor/substrate recognition and should prove helpful in the further development of novel antibiotics based on the inhibition of SPase I.
Luo
Chuanyun
C
Department of Molecular Biology and Biochemistry, Simon Fraser University, South Science Building 8888 University Drive, Burnaby, British Columbia, V5A 1S6 Canada.
Roussel
Patrick
P
Dreier
Jürg
J
Page
Malcolm G P
MG
Paetzel
Mark
M
D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D007700:Kinetics; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000737:chemistry; D012697:Serine Endopeptidases / Q000737:chemistry*; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D055672:Static Electricity; D013449:Sulfonamides / Q000737:chemistry / Q000494:pharmacology
D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D009842:Oligopeptides; D010446:Peptide Fragments; D015842:Serine Proteinase Inhibitors; D013449:Sulfonamides; C488532:arylomycin A2; D012697:Serine Endopeptidases; C026515:type I signal peptidase