Image: A graduate student in the department of biochemistry and molecular biology has had a paper published in the Journal of Biological Chemistry. Robert Amos of Dr. Deb Mohnen's lab had "A two-phase model for the non-processive biosynthesis of homogalacturonan polysaccharides by the GAUT1:GAUT7 complex" accepted into the JBC. The article proposes a "two-phase distributive elongation model" in which "a slow phase, which includes the de novo initiation of HG and elongation of short-chain acceptors, is distinguished from a phase of rapid elongation of intermediate and long-chain acceptors," according to the article. This challenges previously reported evidence for a "processive model of (glycosyltransferase) elongation," mainly that "reactions primed with shortchain acceptors resulted in a bimodal product distribution of glycan products," according to the paper. "The paper ... is, I believe, an important milestone in studies of plant cell wall biosynthetic glycosyltransferase complexes, and also important in regards to consideration of processive versus distributive polymer syntheses," Mohnen wrote in an email. The paper is available in full here.