DOI: 10.5061/dryad.pnvx0k6wn
title: Data for: Viral receptor-binding protein evolves new function through mutations that cause trimer instability and functional heterogeneity

description: When proteins evolve new activity, a concomitant decrease in stability is
 often observed because the mutations that confer new activity can
 destabilize the native fold. In the conventional model of protein
 evolution, reduced stability is considered a purely deleterious cost of
 molecular innovation because unstable proteins are prone to aggregation
 and are sensitive to environmental stressors. However, recent work has
 revealed that non-native, often unstable protein conformations play an
 important role in mediating evolutionary transitions, raising the question
 of whether instability can itself potentiate the evolution of new
 activity. We explored this question in a bacteriophage receptor binding
 protein (RBP) during host-range evolution. We studied the properties of
 the RBP of bacteriophage  before and after host-range evolution
 and demonstrated that the evolved protein is relatively unstable and may
 exist in multiple conformations with unique receptor preferences. Through
 a combination of structural modeling and in vitro oligomeric state
 analysis, we found that the instability arises from mutations that
 interfere with trimer formation. This study raises the intriguing
 possibility that protein instability might play a previously unrecognized
 role in mediating host-range expansions in viruses.
description: Biochemical assays of bacteriophage lambda's receptor
 binding protein. 
description: # Data for: Viral receptor-binding protein evolves new function through
 mutations that cause trimer instability and functional heterogeneity
 [https://doi.org/10.5061/dryad.pnvx0k6wn](https://doi.org/10.5061/dryad.pnvx0k6wn) Give a brief summary of dataset contents, contextualized in experimental procedures and results. ## Description of the data and file structure fig2a_RFU.csv - Data displayed in Figure 2 panel A. First column is the temperature, the next nine columns give the fluorescence at the different temperatures. The first three of the columns are replicates of a buffer control, the next set of three are for the ancestral protein, and the last three are for the evolved protein. fig2b_dRFUdt.csv - Data displayed in Figure 2 panel B. First column is the temperature, the next nine columns give the first derivative of the melting curve at the different temperatures. The first three of the columns are replicates of a buffer control, the next set of three are for the ancestral protein, and the last three are for the evolved protein. Fig3_SEC_MALS_ancestor and evolved.csv - Data from the SEC-MALS run of both proteins. The first two columns give information on the ancestral protein's dRI (RIU) and the second two on the molecular weight. The second set of four columns provide information on the evolved protein. The 5th and 6th columns are of the protein's dRI (RIU) and 7 and 8 are on the molecular weight. Some spreadsheet cells are missing data, these are indicated by n/a. fig4_data_combined.csv - Provides data displayed in Figure 4a and 4c (4b and 4d are derived from 4a and 4c, respectively), data are combined into a single spreadsheet. The first column specifies which protein was being studied, the ancestor 'mbp-his-J250-ci857' or evolved 'mbp-his-J250-evoc'. The second defines the replicate. The third column gives the receptor the protein is interacting with (LamB is the native receptor, OmpF is the novel receptor). The next column defines whether the measurement was made before or after exposing the protein to high temperatures (40 C for 30 minutes). The last column gives the fraction of the phage that are blocked by the protein from binding the receptors.