1dk0
From Proteopedia
CRYSTAL STRUCTURE OF THE HEMOPHORE HASA FROM SERRATIA MARCESCENS CRYSTAL FORM P2(1), PH8
Overview
The protein HasA from the Gram negative bacteria Serratia marcescens is the first hemophore to be described at the molecular level. It participates to the shuttling of heme from hemoglobin to the outer membrane receptor HasR, which in turn releases it into the bacterium. HasR alone is also able to take up heme from hemoglobin but synergy with HasA increases the efficiency of the system by a factor of about 100. This iron acquisition system allows the bacteria to survive with hemoglobin as the sole iron source. Here we report the structures of a new crystal form of HasA diffracting up to 1.77A resolution as well as the refined structure of the trigonal crystal form diffracting to 3.2A resolution. The crystal structure of HasA at high resolution shows two possible orientations of the heme within the heme-binding pocket, which probably are functionally involved in the heme-iron acquisition process. The detailed analysis of the three known structures reveals the molecular basis regulating the relative affinity of the heme/hemophore complex.
About this Structure
1DK0 is a Single protein structure of sequence from Serratia marcescens. Full crystallographic information is available from OCA.
Reference
Functional aspects of the heme bound hemophore HasA by structural analysis of various crystal forms., Arnoux P, Haser R, Izadi-Pruneyre N, Lecroisey A, Czjzek M, Proteins. 2000 Nov 1;41(2):202-10. PMID:10966573 Page seeded by OCA on Fri May 2 13:56:11 2008
