Until recently, little progress has been made in determining high-resolution structural data for membrane proteins--the transporters, channels, and receptors that play critical roles in cell physiology. Now, scientists say they might be seeing the trickle that precedes the deluge. The current explosion of genomic information has led to the identification of prokaryotic homologs for many eukaryotic transporters and channels. These prokaryotic counterparts offer distinct advantages for crystallization, both in their diversity and ease of production. And while not every feature can be extrapolated to eukaryotes, the results could fill a few gaps in knowledge.
"Membrane protein structure determination is taking off," writes Declan Doyle, University of Oxford, in an E-mail. Doyle and his group have solved the structure of the KirBac1.1 potassium channel from Burkholderia pseudomallei.1 This so-called inwardly rectifying channel protein allows unidirectional flow of potassium ions into cells, and it represents an important advance, says Doyle. "We have ...
