Study results from Texas A&M University update understanding of bacteriology
2007 NOV 13 -- Scientists discuss in 'The T4 RI antiholin has an N-terminal signal anchor release domain that targets it for degradation by DegP' new findings in bacteriology. According to recent research from the United States, "Lysis inhibition (LIN) of T4-infected cells was one of the foundational experimental systems for modern molecular genetics. In LIN, secondary infection of T4-infected cells results in a dramatically protracted infection cycle in which intracellular phage and endolysin accumulation can continue for hours." "At the molecular level, this is due to the inhibition of the holin, T, by the antiholin, RI. RI is only 97 residues and contains an N-terminal hydrophobic domain and a C-terminal hydrophilic domain; expression of the latter domain fused to a secretory signal sequence is sufficient to impose LIN, due to its specific interaction with the periplasmic domain of the T holin. Here we show that the N-terminal sequence comprises a signal anchor release (SAR) domain, which causes the secretion of RI in a membrane-tethered form and then its subsequent release into the periplasm, without proteolytic processing. Moreover, the SAR domain confers both functional lability and DegP-mediated proteolytic instability on the released form of RI, although LIN is not affected in a degP host," wrote T.A. Tran and colleagues, Texas A&M University. The researchers concluded: "These results are discussed in terms of a model for the activation of RI in the establishment of the LIN state." Tran and colleagues published their study in the Journal of Bacteriology (The T4 RI antiholin has an N-terminal signal anchor release domain that targets it for degradation by DegP. Journal of Bacteriology, 2007;189(21):7618-25). For additional information, contact T.A. Tran, Texas A&M University, Dept. of Biochemistry and Biophysics, 2128 TAMU, College Station, TX 77843-2128 USA.. Publisher contact information for the Journal of Bacteriology is: American Society Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA. Keywords: United States, College Station, Bacteriology. This article was prepared by Science Letter editors from staff and other reports. Copyright 2007, Science Letter via NewsRx.com.
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