Mutant Flavin-Based Fluorescent Protein Sensors for Detecting Intracellular Zinc and Copper in Escherichia coli.

ABSTRACT: Flavin-based fluorescent proteins (FbFPs) are a class of fluorescent reporters that undergo oxygen-independent fluorophore incorporation, which is an important advantage over green fluorescent proteins (GFPs) and mFruits. A FbFP derived from Chlamydomonas reinhardtii (CreiLOV) is a promising platform for designing new metal sensors. Some FbFPs are intrinsically quenched by metal ions, but the question of where metals bind and how to tune metal affinity has not been addressed. We used site-directed mutagenesis of CreiLOV to probe a hypothesized copper(II) binding site that led to fluorescence quenching. Most mutations changed the fluorescence quenching level, supporting the proposed site. One key mutation introducing a second cysteine residue in place of asparagine (CreiLOV_N41C<

SUBMITTER: Zou W 

PROVIDER: S-EPMC9888404 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature