The long term objective of this research effort is to elucidate the molecular mechanisms by which bacteriophage accomplish lysis of the host. Phage lysis is a fundamental phenomenon involving molecules which interact with the host cell membrane and with bacterial cell wall structures. Moreover, the process of host lysis must be carefully scheduled by the bacteriophage in order to optimize the production of virions. Thus lessons learned from the study of phage lysis are likely to be important to the understanding of cell membrane structure and dynamics and the regulation of viral proliferation in general, as well as providing insights into the structure, function, and metabolism of the bacterial envelope. Phage systems provide powerful genetic tools, which we propose to use in a study of the lysis systems of lambda and related phage and of the phage phiX174, representing the two fundamental strategies of host lysis. We will conduct a genetic analysis of the lambda S gene, encoding the prototype """"""""holin"""""""", which functions to allow passage of the soluble endolysin, or lysozyme, across the cell membrane. Our approach uses positive and negative selections for holin function using plasmid and phage vectors. A mutational study of a functional homolog from phage 21 will be conducted to determine what features of the 21 holin are common with the lambda holin. Intragenic suppression and complementation will be used to establish a point-to-point interaction-map within the holin sequence. Clock mutants defective in the timing of lysis will be isolated and characterized. An in vitro hole forming assay will be developed using planar lipid membranes or small unilamellar vesicles. The interaction between the phiX174 E lysis protein and the host protein SlyD, which is a homolog of the human FKBP immunophilin, will be investigated using genetic and molecular means.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37GM027099-19
Application #
2634630
Study Section
Special Emphasis Panel (ZRG5-MBC-1 (02))
Project Start
1980-01-01
Project End
2000-12-31
Budget Start
1998-01-01
Budget End
1998-12-31
Support Year
19
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Texas A&M University
Department
Biochemistry
Type
Schools of Earth Sciences/Natur
DUNS #
047006379
City
College Station
State
TX
Country
United States
Zip Code
77845
Kongari, Rohit; Rajaure, Manoj; Cahill, Jesse et al. (2018) Phage spanins: diversity, topological dynamics and gene convergence. BMC Bioinformatics 19:326
Chamakura, Karthik R; Tran, Jennifer S; Young, Ry (2017) MS2 Lysis of Escherichia coli Depends on Host Chaperone DnaJ. J Bacteriol 199:
Cui, Zhicheng; Gorzelnik, Karl V; Chang, Jeng-Yih et al. (2017) Structures of Q? virions, virus-like particles, and the Q?-MurA complex reveal internal coat proteins and the mechanism of host lysis. Proc Natl Acad Sci U S A 114:11697-11702
Cahill, Jesse; Rajaure, Manoj; O'Leary, Chandler et al. (2017) Genetic Analysis of the Lambda Spanins Rz and Rz1: Identification of Functional Domains. G3 (Bethesda) 7:741-753
Chamakura, Karthik R; Sham, Lok-To; Davis, Rebecca M et al. (2017) A viral protein antibiotic inhibits lipid II flippase activity. Nat Microbiol 2:1480-1484
Cahill, Jesse; Rajaure, Manoj; Holt, Ashley et al. (2017) Suppressor Analysis of the Fusogenic Lambda Spanins. J Virol 91:
Chamakura, Karthik R; Edwards, Garrett B; Young, Ry (2017) Mutational analysis of the MS2 lysis protein L. Microbiology 163:961-969
Gorzelnik, Karl V; Cui, Zhicheng; Reed, Catrina A et al. (2016) Asymmetric cryo-EM structure of the canonical Allolevivirus Q? reveals a single maturation protein and the genomic ssRNA in situ. Proc Natl Acad Sci U S A 113:11519-11524
Chen, Yi; Young, Ry (2016) The Last r Locus Unveiled: T4 RIII Is a Cytoplasmic Antiholin. J Bacteriol 198:2448-57
Young, Ry; Gill, Jason J (2015) MICROBIOLOGY. Phage therapy redux--What is to be done? Science 350:1163-4

Showing the most recent 10 out of 90 publications