Bright and stable monomeric green fluorescent protein derived from StayGold
The high brightness and photostability of the green fluorescent protein StayGold make it a particularly attractive probe for long-term live-cell imaging; however, its dimeric nature precludes its application as a fluorescent tag for some proteins. Here, we report the development and crystal structures of a monomeric variant of StayGold, named mBaoJin, which preserves the beneficial properties of its precursor, while serving as a tag for structural proteins and membranes. Systematic benchmarking of mBaoJin against popular green fluorescent proteins and other recently introduced monomeric and pseudomonomeric derivatives of StayGold established mBaoJin as a bright and photostable fluorescent protein, exhibiting rapid maturation and high pH/chemical stability. mBaoJin was also demonstrated for super-resolution, long-term live-cell imaging and expansion microscopy. We further showed the applicability of mBaoJin for neuronal labeling in model organisms, including Caenorhabditis elegans and mice.
The PDB IDs are 8QBJ, 8Q79 and 8QDD for atomic structures of mBaoJin crystallized at pH 4.6, pH 6.5 and pH 8.5, respectively. The total size of the files acquired for this study exceeds the 20-GB limit of the FigShare repository, therefore only the most essential raw datasets, including source files for supplementary figures and raw unprocessed images, are available at figshare (https://doi.org/10.6084/m9.figshare.25001768). The remaining files are available from the corresponding author upon request. All plasmids used in this study are available from WeKwikGene (https://wekwikgene.wllsb.edu.cn/). Source data are provided with this paper.
