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Ry Young

Young, Ry
Ry Young
University Distinguished Professor, Professor of Biochemistry and Biophysics and Biology
BioBio / Room 311A
Undergraduate Education
A.B. Rice University (1968)
Graduate Education
Ph.D. University of Texas, Dallas (1975)
Postdoc. Harvard Medical School (1975-78)
Joined Texas A&M in 1978

The Molecules and Mechanisms of Bacteriophage Lysis

Most bacterial viruses (phages) cause lysis of their host cell to release the progeny virions. Large phages elaborate an enzyme (“endolysin”) to degrade the cell wall and also a small membrane protein (“holin”). The holin accumulates in the membrane and then, at a precisely scheduled time, suddenly forms a hole to allow release of endolysin through the cytoplasmic membrane to gain access to the wall. We use molecular genetics and biochemistry to study how this small protein is able to act as a molecular “clock” and punch holes in membranes. Small phages make single proteins which cause host lysis in a different way. This strategy is to target the host cell wall synthesis machinery; that is, the virus makes a “protein antibiotic” that causes lysis in the same way as antibiotics like penicillin by inhibiting an enzyme in the multi-step pathway of murein biosynthesis. Thus, when the infected cell tries to divide, it blows up, or lyses, because it can’t make the new cell wall between the daughter cells. Remarkably, each of three different, small phages blocks a different step in the pathway. These small lysis proteins are models for a completely new class of antibacterial antibiotics. Also, the E. coli SlyD protein is required for this mode of lysis in one case. SlyD is a member of an ubiquitous family of proteins related to human “immunophilins,” the targets of immune-suppression drugs. We study SlyD to learn about the role of this class of proteins in biology.

Recent Publications

  1. Cahill, J, Young, R. Phage Lysis: Multiple Genes for Multiple Barriers. Adv. Virus Res. 2019;103 :33-70.
    doi: 10.1016/bs.aivir.2018.09.003. PubMed PMID:30635077. .

  2. Schooley, RT, Biswas, B, Gill, JJ, Hernandez-Morales, A, Lancaster, J, Lessor, L et al.. Erratum for Schooley et al., "Development and Use of Personalized Bacteriophage-Based Therapeutic Cocktails To Treat a Patient with a Disseminated Resistant Acinetobacter baumannii Infection". Antimicrob. Agents Chemother. 2018;62 (12):.
    doi: 10.1128/AAC.02221-18. PubMed PMID:30478181. PubMed Central PMC6256779.

  3. Kongari, R, Rajaure, M, Cahill, J, Rasche, E, Mijalis, E, Berry, J et al.. Phage spanins: diversity, topological dynamics and gene convergence. BMC Bioinformatics. 2018;19 (1):326.
    doi: 10.1186/s12859-018-2342-8. PubMed PMID:30219026. PubMed Central PMC6139136.

  4. Kongari, R, Snowden, J, Berry, JD, Young, R. Localization and Regulation of the T1 Unimolecular Spanin. J. Virol. 2018;92 (22):.
    doi: 10.1128/JVI.00380-18. PubMed PMID:30135120. PubMed Central PMC6206483.

  5. Trinh, JT, Alkahtani, MH, Rampersaud, I, Rampersaud, A, Scully, M, Young, RF et al.. Fluorescent nanodiamond-bacteriophage conjugates maintain host specificity. Biotechnol. Bioeng. 2018;115 (6):1427-1436.
    doi: 10.1002/bit.26573. PubMed PMID:29460442. PubMed Central PMC5912989.

  6. Gill, JJ, Wang, B, Sestak, E, Young, R, Chu, KH. Characterization of a Novel Tectivirus Phage Toil and Its Potential as an Agent for Biolipid Extraction. Sci Rep. 2018;8 (1):1062.
    doi: 10.1038/s41598-018-19455-2. PubMed PMID:29348539. PubMed Central PMC5773508.

  7. Hernandez-Morales, AC, Lessor, LL, Wood, TL, Migl, D, Mijalis, EM, Russell, WK et al.. Genomic and Biochemical Characterization of Acinetobacter Podophage Petty Reveals a Novel Lysis Mechanism and Tail-Associated Depolymerase Activity. J. Virol. 2018; :.
    doi: 10.1128/JVI.01064-17. PubMed PMID:29298884. PubMed Central PMC5827379.

  8. Cui, Z, Gorzelnik, KV, Chang, JY, Langlais, C, Jakana, J, Young, R et al.. Structures of Qβ virions, virus-like particles, and the Qβ-MurA complex reveal internal coat proteins and the mechanism of host lysis. Proc. Natl. Acad. Sci. U.S.A. 2017;114 (44):11697-11702.
    doi: 10.1073/pnas.1707102114. PubMed PMID:29078304. PubMed Central PMC5676892.

  9. Chamakura, KR, Sham, LT, Davis, RM, Min, L, Cho, H, Ruiz, N et al.. A viral protein antibiotic inhibits lipid II flippase activity. Nat Microbiol. 2017;2 (11):1480-1484.
    doi: 10.1038/s41564-017-0023-4. PubMed PMID:28894177. PubMed Central PMC5764540.

  10. Schooley, RT, Biswas, B, Gill, JJ, Hernandez-Morales, A, Lancaster, J, Lessor, L et al.. Development and Use of Personalized Bacteriophage-Based Therapeutic Cocktails To Treat a Patient with a Disseminated Resistant Acinetobacter baumannii Infection. Antimicrob. Agents Chemother. 2017;61 (10):.
    doi: 10.1128/AAC.00954-17. PubMed PMID:28807909. PubMed Central PMC5610518.

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