A bacterial dual positive and negative selection system for dCas9 activity.

The engineering of switchable or activatable dCas9 proteins would benefit from a single system for both positive and negative selection of dCas9 activity. Most systems that are used to interrogate dCas9 libraries use a fluorescent protein screen or an antibiotic selection for active dCas9 variants....

Full description

Saved in:
Bibliographic Details
Main Authors: Shaun Spisak, Brett O'Brien, Marc Ostermeier
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0269270&type=printable
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849773622642606080
author Shaun Spisak
Brett O'Brien
Marc Ostermeier
author_facet Shaun Spisak
Brett O'Brien
Marc Ostermeier
author_sort Shaun Spisak
collection DOAJ
description The engineering of switchable or activatable dCas9 proteins would benefit from a single system for both positive and negative selection of dCas9 activity. Most systems that are used to interrogate dCas9 libraries use a fluorescent protein screen or an antibiotic selection for active dCas9 variants. To avoid some of the limitations of these systems, we have developed a single system capable of selecting for either active or inactive dCas9 variants. E. coli expressing active dCas9 variants are isolated in the positive selection system through growth in the presence of ampicillin. The negative selection can isolate cells lacking dCas9 activity through two separate mechanisms: growth in M9 minimal media or growth in media containing streptomycin. This system is capable of enriching for rare dCas9 variants up to 9,000-fold and possesses potential utility in directed evolution experiments to create switchable dCas9 proteins.
format Article
id doaj-art-54450482c9ef40349fb4200a28fa32e5
institution DOAJ
issn 1932-6203
language English
publishDate 2022-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-54450482c9ef40349fb4200a28fa32e52025-08-20T03:01:59ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-01176e026927010.1371/journal.pone.0269270A bacterial dual positive and negative selection system for dCas9 activity.Shaun SpisakBrett O'BrienMarc OstermeierThe engineering of switchable or activatable dCas9 proteins would benefit from a single system for both positive and negative selection of dCas9 activity. Most systems that are used to interrogate dCas9 libraries use a fluorescent protein screen or an antibiotic selection for active dCas9 variants. To avoid some of the limitations of these systems, we have developed a single system capable of selecting for either active or inactive dCas9 variants. E. coli expressing active dCas9 variants are isolated in the positive selection system through growth in the presence of ampicillin. The negative selection can isolate cells lacking dCas9 activity through two separate mechanisms: growth in M9 minimal media or growth in media containing streptomycin. This system is capable of enriching for rare dCas9 variants up to 9,000-fold and possesses potential utility in directed evolution experiments to create switchable dCas9 proteins.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0269270&type=printable
spellingShingle Shaun Spisak
Brett O'Brien
Marc Ostermeier
A bacterial dual positive and negative selection system for dCas9 activity.
PLoS ONE
title A bacterial dual positive and negative selection system for dCas9 activity.
title_full A bacterial dual positive and negative selection system for dCas9 activity.
title_fullStr A bacterial dual positive and negative selection system for dCas9 activity.
title_full_unstemmed A bacterial dual positive and negative selection system for dCas9 activity.
title_short A bacterial dual positive and negative selection system for dCas9 activity.
title_sort bacterial dual positive and negative selection system for dcas9 activity
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0269270&type=printable
work_keys_str_mv AT shaunspisak abacterialdualpositiveandnegativeselectionsystemfordcas9activity
AT brettobrien abacterialdualpositiveandnegativeselectionsystemfordcas9activity
AT marcostermeier abacterialdualpositiveandnegativeselectionsystemfordcas9activity
AT shaunspisak bacterialdualpositiveandnegativeselectionsystemfordcas9activity
AT brettobrien bacterialdualpositiveandnegativeselectionsystemfordcas9activity
AT marcostermeier bacterialdualpositiveandnegativeselectionsystemfordcas9activity