Open AccessUsing surface‐bound rubidium ions for protein phasing
Author(s) -
Korolev S.,
Dementieva I.,
Sanishvili R.,
Minor W.,
Otwinowski Z.,
Joachimiak A.
Publication year - 2001
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444901007302
Subject(s) - rubidium , thermus thermophilus , crystallography , ion , chemistry , counterion , crystal structure , potassium , biochemistry , organic chemistry , escherichia coli , gene
Rubidium is a monovalent metal that can be used as a counterion in protein solutions. X‐ray anomalous scattering from rubidium ions bound to the protein surface was used for phasing of the crystal structure of the hsp60 apical domain from Thermus thermophilus . Multiple‐wavelength anomalous dispersion (MAD) data were collected from a crystal obtained from a solution containing 0.2 M rubidium salt. One molecule of protein (147 amino acids) binds one well ordered and one poorly ordered Rb atom. Phases calculated with the program SHARP were sufficient for automatic tracing and side‐chain assignment using the program ARP / wARP . The data show that bound rubidium ions can be used to determine protein structures and to study the interaction of monovalent metal ions with proteins and other macromolecules.