Antibody production: an endurance sport

To understand recent research from immunologist Jerry Boss’s lab on antibody production, think about the distinction between sprinting and long-distance Read more

Less mucus, more neutrophils: alternative view of CF

A conventional view of cystic fibrosis (CF) and its effects on the lungs is that it’s all about mucus. Rabin Tirouvanziam has an alternative view, centered on Read more

translation

Toe in the water for Emory cryo-EM structures

Congratulations to Christine Dunham and colleagues in the Department of Biochemistry for their first cryo-electron microscopy paper, recently published in the journal Structure.

The paper solves the structure of a bacterial ribosome bound to a messenger RNA containing a loop that regulates translation. This process is important for the study of several neurological diseases such as fragile X syndrome, for example.

Christine Dunham, PhD

Dunham writes: “We are focusing on establishing this in bacteria to understand frameshifting and protein folding as a consequence of codon preference. We will then build up our knowledge to potentially study eukaryotic translational control.”

The paper neatly links up with two Nobel Prizes: the 2017 Chemistry prize for cryo-electron microscopy and the 2009 Chemistry prize for ribosome structure, awarded in part to Dunham’s mentor Venki Ramakrishnan. Also, see this 2015 feature from Nature’s Ewen Callaway outlining how cryo-EM is a must have for structural biologists wanting to probe large molecules that are difficult to crystallize.

Construction now underway in the Biochemistry Connector will allow installation of microscopes (worth $6 million) necessary for Dunham and others to do cryo-EM here at Emory, although she advises that it will be several months until they are photo-op ready. For the Structure paper, Dunham collaborated with George Skiniotis at University of Michigan; he recently moved to Stanford. Read more

Posted on by Quinn Eastman in Neuro, Uncategorized Leave a comment

From the genetic code to new antibiotics

Biochemist Christine Dunham and her colleagues have a new paper in PNAS illuminating a long-standing puzzle concerning ribosomes, the factories inside cells that produce proteins.

Ribosomes are where the genetic code “happens,” because they are the workshops where messenger RNA is read out and proteins are assembled piece by piece. As a postdoc, Dunham contributed to Nobel Prize-winning work determining the molecular structure of the ribosome with mentor Venki Ramakrishnan.

Ribosomes are the workshops for protein synthesis and the targets of several antibiotics

The puzzle is this: how messenger RNA can be faithfully and precisely translated, when the interactions that hold RNA base pairs (A-U and G-C) together are not strong enough. There is enough “wobble” in RNA base pairing such that transfer RNAs that don’t match all three letters on the messenger RNA can still fit.

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Posted on by Quinn Eastman in Uncategorized Leave a comment