W0478

The Neutron Diffraction Structure of a Single Mutant of Rubredoxin from Pyrococcus furiosus. Xinmin Li,^a Paul Langan^a,* Irina Tsyba, ^b Robert Bau ^b, Benno P. Schoenborn^a, ^aBioscience Division, Los Alamos National Laboratory, Los Alamos NM 87545, ^bUniv. of Southern Cailfornia, Los Angeles CA 90089, *Corresponding Author: M888, Los Alamos National Laboratory, Los Alamos NM 87545, langan_paul@lanl.gov.

Rubredoxin from Pyrocuccus furious, a thermophilic archaebacterium found near geothermal vents on the ocean floor, maintains its native structure at high temperatures (100^oC). In order to study its thermostability the hydrogen bonding pattern between the native protein and a series of mutants are being investigated using neutron diffraction. The neutron structures of the wild-type protein and a triple mutant have already been determined using data collected on BIX-3 at JAERI (Kurihara et al, 2001 Chatake et al, 2002). This poster will present the neutron structure of a single mutant (Trp3 → Tyr3) determined from data collected at the spallation neutron Protein Crystallography Station (PCS) at Los Alamos. Data were collected at 9 crystal settings for 12 hours at each setting, over a period of 4-5 days. In total 5357 reflections were recorded for 2184 unique reflections up to 2.1Å, covering 69.4% of the unique section, with the completeness in outer shell 2.1Å-2.2Å 63%. The structure provides a wealth of data on protein hydration and hydrogen bonded which is being compared to information from the triple mutant and the wild type.