Floyd Bryant, PhD
615 N. Wolfe Street, W8025
Baltimore , Maryland 21205
PhD , Stanford University , 1981
Our laboratory is broadly interested in enzymatic mechanisms in DNA biochemistry. Our current research is focused on a process known as transformational recombination which occurs in the major human pathogen, Streptococcus pneumoniae. S. pneumoniae is a naturally transformable bacterium that is able to take up DNA from its environment and incorporate this exogenous DNA into its own chromosome. This process serves as a general mutational mechanism which in recent years has allowed S. pneumoniae to develop resistance to various classes of antibiotics.
We have isolated and analyzed many of the proteins which have been shown by genetic analysis to be involved in transformational recombination, or required for S. pneumoniae viability in general. These include the S. pneumoniae RecA protein (a DNA recombinase), the SsbA and SsbB proteins (two single stranded DNA binding proteins), the MmsA protein (a DNA helicase), the RecO and RecR proteins (two recombinase accessory proteins), the DprA protein (a likely recombination accessory protein), and the YqgF protein (a potential DNA junction binding protein). Our continuing investigations of the coordinated action of these key proteins are aimed at determining the biochemical mechanism of transformational recombination, and will provide insight into the molecular basis for the development of antibiotic resistance in Streptococcus pneumoniae and related human pathogens.
Biochemistry and molecular biology, E. coli, Streptococcus, RecA, strand-exchange, ATP hydrolysis, recombination, DNA repair
Grove, D.E., Anne, G., Hedayati, M.A., and Bryant, F.R. (2012) "Stimulation of the Streptococcus pneumoniae RecA protein-promoted three-strand exchange reaction by the competence-specific SsbB protein" Biochem. Biophys. Res. Comm. 424:40-44.
Steffen, S.E. and Bryant, F.R. (2012) "Altered nucleotide cofactor-dependent properties of the mutant [S240K]RecA protein" Biochem. Biophys. Res. Comm. 421:527-531.
Salerno, B., Anne, G., and Bryant, F.R. (2011) "DNA binding compatibility of the Streptococcus pneumoniae SsbA and SsbB proteins" PLoS ONE 6(9):e24305.
Grove, D.E., and Bryant, F.R. (2006) "Effect of Mg(2+) on the DNA binding modes of the Streptococcus pneumoniae SsbA and SsbB Proteins" J. Biol.Chem.281:2087-2094.
Grove, D.E., Willcox, S., Griffith, J.D., and Bryant, F.R. (2005) "Differential single-stranded DNA binding properties of the paralogous SsbA and SsbB proteins from Streptococcus pneumoniae" J. Biol. Chem. 280:11067-11073.