November 2011

pH uniquely modulates protein arginine methylation

Protein arginine methyltransferases (PRMTs) function in the alkaline milieu of the nucleus and at neutral pH of the cytosol. Accordingly, several PRMTs are broadly active over a range of pHs. We investigated the effect altering pH had on protein arginine methylation using a variety of defined substrates, recombinant PRMTs and cell extracts.We demonstrate that pH-induced alterations in the extent of methylation and the...

Author(s): Wen Xie, George Merz and Robert B. Denman

November 2011

Crystal structure of the allosteric-defective chaperonin GroELE434K mutant

The chaperonin GroEL adopts a double-ring structure with various modes of allosteric communication. The simultaneous positive intra-ring and negative inter-ring cooperativities allow alternating functionality of the folding cavities in both protein rings. Mutation of glutamic acid 434 (located at the ring interface), to lysine alters the negative inter-ring cooperativity. The crystal structure of the mutant chaperonin...

Author(s): Aintzane Cabo-Bilbao, Ariel E. Mechaly, Jon Agirre, Silvia Spinelli, Begoña Sot, Arturo Muga and Diego M.A. Guérin