TonB-Dependent Heme/Hemoglobin Utilization by Caulobacter crescentus HutA.

ABSTRACT: Siderophore nutrition tests with Caulobacter crescentus strain NA1000 revealed that it utilized a variety of ferric hydroxamate siderophores, including asperchromes, ferrichromes, ferrichrome A, malonichrome, and ferric aerobactin, as well as hemin and hemoglobin. C. crescentus did not transport ferrioxamine B or ferric catecholates. Because it did not use ferric enterobactin, the catecholate aposiderophore was an effective agent for iron deprivation. We determined the kinetics and thermodynamics of [59Fe]apoferrichrome and 59Fe-citrate binding and transport by NA1000. Its affinity and uptake rate for ferrichrome (equilibrium dissociation constant [Kd ], 1 nM; Michaelis-Menten constant [KM ], 0.1 nM; Vmax, 19 pMol/109 cells/min) were similar to those of Escherichia coli FhuA. Transport pro

SUBMITTER: Balhesteros H 

PROVIDER: S-EPMC5331666 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature