My lab is focused on identifying and functionally characterizing proteins containing fifty or fewer amino acids. The prevalence and physiological function of such small proteins are poorly understood in any organism. To address these biological questions, we are using the model bacterium Escherichia coli. We have recently found that E. coli contains many more small proteins than had been previously predicted. Further analysis has shown that many of these proteins are expressed under specific environmental conditions, suggesting that they have interesting functions in the cell. Our current goals include continuing to characterize small protein function in E. coli, in particular those small proteins that are predicted to span the membrane with a single hydrophobic a-helix. These transmembrane small proteins make up the majority of small proteins identified in E. coli, and could be performing a wide range of functions at the membrane. Ultimately, the information we learn about E. coli small proteins will provide a foundation for investigating small protein abundance and function in both other bacteria species and eukaryotes.
VanOrsdel CE, Bhatt S, Allen RJ, Brenner EP, Hobson JJ, Jamil A, Haynes BM, Genson AM, Hemm MR (2013) The Escherichia coli CydX protein is a member of the CydAB cytochrome bd oxidase complex and is required for cytochrome bd oxidase activity. J Bacteriol 195:3640-3650. doi: 10.1128/JB.00324-13
Opdyke JA, Fozo EM, Hemm MR, Storz G (2011) RNase III participates in GadY-dependent cleavage of the gadX-gadW mRNA. J Mol Biol 406:29-43. doi: 10.1016/j.jmb.2010.12.009
Hemm MR, Paul BJ, Miranda-Rios J, Hobbs EC, Soltanzad N, Storz G (2010) Small stress response proteins in Escherichia coli: Proteins missed by classical proteomics studies. J Bac 192: 46-58.
Fozo EM*, Hemm MR*, Storz G (2008) Small toxic proteins and the antisense RNAs that repress them. Microbiol Mol Biol Rev 72: 579-589. (*authors contributed equally)
Hemm MR, Paul BJ, Schneider TD, Storz G, Rudd KE. (2008) Small membrane proteins found by comparative genomics and ribosome binding site models. Mol Micro 70: 1487-1501.