University of Oregon scientists have discovered how the bacterium Helicobacter pylori navigates through the acidic stomach, opening up new possibilities to inactivate its disease-causing ability without using current strategies that often fail or are discontinued because of side effects.
Their report -- online ahead of regular publication July 3 in the journal Structure -- unveils the crystal structure of H. pylori's acid receptor TlpB. The receptor has an external protrusion, identified as a PAS domain, bound by a small molecule called urea and is poised to sense the external environment. TlpB is the first bacterial chemoreceptor of known function shown by crystallography to contain an extracellular PAS domain, the researchers reported.
"It is a beautiful structure, and this domain has never been seen before in this class of proteins," said co-author S. James Remington, professor of physics and member of the UO Institute of Molecular Biology. Captured at the atomic resolution of 1.38 angstroms, it is the first new, significant structural view in 20 years of the class of receptors used by bacteria to navigate their chemical environment.