Mapping the functional landscape of the receptor binding domain of T7 bacteriophage by deep mutational scanning

eLife

Megan Leander¹  Kyle Nishikawa¹  Anthony Meger¹  Phil Huss²  Srivatsan Raman³ 

[1] Department of Biochemistry, University of Wisconsin-Madison, Madison, United States;Department of Biochemistry, University of Wisconsin-Madison, Madison, United States;Department of Bacteriology, University of Wisconsin-Madison, Madison, United States;Department of Biochemistry, University of Wisconsin-Madison, Madison, United States;Department of Bacteriology, University of Wisconsin-Madison, Madison, United States;Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, United States;

关键词: Bacteriophage;    phage;    virus;    deep mutational scanning;    synthetic biology;    tail fiber;    Virus;   

DOI  :  10.7554/eLife.63775

来源: eLife Sciences Publications, Ltd

【 摘 要 】

The interaction between a bacteriophage and its host is mediated by the phage's receptor binding protein (RBP). Despite its fundamental role in governing phage activity and host range, molecular rules of RBP function remain a mystery. Here, we systematically dissect the functional role of every residue in the tip domain of T7 phage RBP (1660 variants) by developing a high-throughput, locus-specific, phage engineering method. This rich dataset allowed us to cross compare functional profiles across hosts to precisely identify regions of functional importance, many of which were previously unknown. Substitution patterns showed host-specific differences in position and physicochemical properties of mutations, revealing molecular adaptation to individual hosts. We discovered gain-of-function variants against resistant hosts and host-constricting variants that eliminated certain hosts. To demonstrate therapeutic utility, we engineered highly active T7 variants against a urinary tract pathogen. Our approach presents a generalized framework for characterizing sequence–function relationships in many phage–bacterial systems.

【 授权许可】

CC BY