Structure of the Bacillus anthracis dTDP-l-rhamnose-biosynthetic enzyme glucose-1-phosphate thymidylyltransferase (RfbA)

In this study, the three-dimensional structure of the first protein of this pathway, glucose-1-phosphate thymidylyltransferase (RfbA), from Bacillus anthracis was determined. In other organisms this enzyme is referred to as RmlA. RfbA was co-crystallized with the products of the enzymatic reaction, dTDP- α -d-glucose and pyrophosphate, and its structure was determined at 2.3   Å resolution. This is the first reported thymidylyltransferase structure from a Gram-positive bacterium. RfbA shares overall structural characteristics with known RmlA homologs. However, RfbA exhibits a shorter sequence at its C-terminus, which results in the absence of three α -helices involved in allosteric site formation. Consequently, RfbA was observed to exhibit a quaternary structure that is unique among currently reported glucose-1-phosphate thymidylyltransferase bacterial homologs. These structural analyses suggest that RfbA may not be allosterically regulated in some organisms and is structurally distinct from other RmlA homologs.

Source: Acta Crystallographica Section F - October 30, 2017 Category: Biochemistry Authors: Baumgartner, J. Lee, J. Halavaty, A.S. Minasov, G. Anderson, W.F. Kuhn, M.L. Tags: RfbA glucose-1-phosphate thymidylyltransferase Bacillus anthracis Anthrax research communications Source Type: research