Category Archives: Dan Tromans

Crystallization and preliminary X-ray analysis of Pac17 from the pacidamycin-biosynthetic cluster of Streptomyces coeruleorubidus

Daniel R. Tromans ; Clare E. M. Stevenson ; Rebecca J. M. Goss ; David M. Lawson

Acta Cryst 2012, F68 971-974

Pac17 is an uncharacterized protein from the pacidamycin gene cluster of the soil bacterium Streptomyces coeruleorubidus. It is implicated in the biosynthesis of the core diaminobutyric acid residue of the antibiotic, although its precise role is uncertain at present. Given that pacidamycins inhibit translocase I of Pseudomonas aeruginosa, a clinically unexploited antibiotic target, they offer new hope in the search for antibacterial agents directed against this important pathogen. Crystals of Pac17 were grown by vapour diffusion and X-ray data were collected at a synchrotron to a resolution of 1.9 Å from a single crystal. The crystal belonged to space group C2, with unit-cell parameters a = 214.12, b = 70.88, c = 142.22 Å, [beta] = 92.96°. Preliminary analysis of these data suggests that the asymmetric unit consists of one Pac17 homotetramer, with an estimated solvent content of 49.0%.

 

Biogenesis of the Unique 4 ‘,5 ‘-Dehydronucleoside of the Uridyl Peptide Antibiotic Pacidamycin

Amany E. Ragab ; Sabine Grüschow ; Daniel R. Tromans ; Rebecca J. M. Goss

JACS 2011, 133 (39) 15288-15291

The pacidamycins belong to a class of antimicrobial nucleoside antibiotics that act by inhibiting the clinically unexploited target translocase I, a key enzyme in peptidoglycan assembly. As with other nucleoside antibiotics, the pacidamycin 4′,5′-dehydronucleoside portion is an essential pharmacophore. Here we show that the biosynthesis of the pacidamycin nucleoside in Streptomyces coeruleorubidus proceeds through three steps from uridine. The transformations involve oxidation of the 5′-alcohol by Pac11, transamination of the resulting aldehyde by Pac5, and dehydration by the Cupin-domain protein Pac13.