Small Regulatory RNAs in the Metal Reducing Bacterium
(2012 - Present)
Brett Pellock, Providence College Mentor: Mary
Allen, Wellesley College
Abstract:Small, non-coding RNAs (sRNAs) are a relatively recently
discovered class of genes that bacteria use to regulate the expression
of other genes in response to changing environmental conditions. sRNAs
function by base pairing to their mRNA targets and mediating either
positive or negative regulatory outcomes. However, sRNA genes in
bacteria are difficult to identify, since they are relatively small
genes and they do not contain the protein-coding signals that demarcate
We have used a computational approach that integrates multiple indices
to predict sRNA genes in the bacterium Shewanella oneidensis. S.
oneidensis is a member of a class of bacteria known as the metalreducing
bacteria. When grown under anaerobic conditions, S. oneidensis can
metabolize soluble, toxic heavy metals into insoluble forms. Thus, it is
of interest to explore the mechanisms that control this potentially
bioremediative function. Our preliminary data suggest that our
predictions will be very useful in identifying sRNAs, including
potential regulators of anaerobic metal-reducing metabolism.
This proposal describes experiments designed to identify and
characterize the function of sRNA genes in S. oneidensis, particularly
those sRNAs that may be involved in regulating heavy metal metabolism.
We are using sRNA gain-of-function and loss-of-function tools to
determine how sRNAs regulate downstream metabolic functions and to
identify the mRNA targets of sRNAs. In addition, we are studying the
role of the RNA chaperone Hfq in sRNA function. Our analyses should
provide novel insights into how sRNA genes are defined, how sRNAs
interact with their targets, and how S. oneidensis heavy metal
metabolism is controlled.