title: The Protein Interactome of Mycobacteriophage Giles Predicts Functions for Unknown Proteins.
abstract: Mycobacteriophages are viruses that infect mycobacterial hosts and are prevalent in the environment. Nearly 700 mycobacteriophage genomes have been completely sequenced, revealing considerable diversity and genetic novelty. Here, we have determined the protein complement of mycobacteriophage Giles by mass spectrometry and mapped its genome-wide protein interactome to help elucidate the roles of its 77 predicted proteins, 50% of which have no known function. About 22,000 individual yeast two-hybrid (Y2H) tests with four different Y2H vectors, followed by filtering and retest screens, resulted in 324 reproducible protein-protein interactions, including 171 (136 nonredundant) high-confidence interactions. The complete set of high-confidence interactions among Giles proteins reveals new mechanistic details and predicts functions for unknown proteins. The Giles interactome is the first for any mycobacteriophage and one of just five known phage interactomes so far. Our results will help in understanding mycobacteriophage biology and aid in development of new genetic and therapeutic tools to understand Mycobacterium tuberculosis.
  
  
  OBJECTIVE
  Mycobacterium tuberculosis causes over 9 million new cases of tuberculosis each year. Mycobacteriophages, viruses of mycobacterial hosts, hold considerable potential to understand phage diversity, evolution, and mycobacterial biology, aiding in the development of therapeutic tools to control mycobacterial infections. The mycobacteriophage Giles protein-protein interaction network allows us to predict functions for unknown proteins and shed light on major biological processes in phage biology. For example, Giles gp76, a protein of unknown function, is found to associate with phage packaging and maturation. The functions of mycobacteriophage-derived proteins may suggest novel therapeutic approaches for tuberculosis. Our ORFeome clone set of Giles proteins and the interactome data will be useful resources for phage interactomics.
authors.affiliation: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA.
authors.forename: Jitender
authors.initials: J
authors.lastname: Mehla
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Rebekah M
authors.initials: RM
authors.lastname: Dedrick
authors.affiliation: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA.
authors.forename: J Harry
authors.initials: JH
authors.lastname: Caufield
authors.affiliation: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Siefring
authors.affiliation: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Mair
authors.affiliation: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Johnson
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Graham F
authors.initials: GF
authors.lastname: Hatfull
authors.affiliation: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA peter@uetz.us.
authors.forename: Peter
authors.initials: P
authors.lastname: Uetz
mesh_terms: D019295:Computational Biology; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D013058:Mass Spectrometry; D009160:Mycobacteriophages / Q000235:genetics / Q000378:metabolism*; D020102:Mycobacterium smegmatis / Q000821:virology*; D009169:Mycobacterium tuberculosis / Q000821:virology; D054730:Protein Interaction Domains and Motifs / Q000502:physiology*; D060066:Protein Interaction Maps; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D014764:Viral Proteins