5VIK

Crystal structure of monomeric near-infrared fluorescent protein miRFP703

Summary for 5VIK

• Entry DOI: 10.2210/pdb5vik/pdb
• Related: 5VIQ 5VIV
• Descriptor: near-infrared fluorescent protein miRFP703, BILIVERDINE IX ALPHA (3 entities in total)
• Functional Keywords: near-infrared fluorescent protein, biliverdin, phytochrome, rpbphp1, fluorescent protein
• Biological source: Rhodopseudomonas palustris
• Total number of polymer chains: 1
• Total formula weight: 35139.59

Authors

Pletnev, S. (deposition date: 2017-04-17, release date: 2017-06-07, Last modification date: 2024-10-23)

Primary citation

Baloban, M.,Shcherbakova, D.M.,Pletnev, S.,Pletnev, V.Z.,Lagarias, J.C.,Verkhusha, V.V.
Designing brighter near-infrared fluorescent proteins: insights from structural and biochemical studies.
Chem Sci, 8:4546-4557, 2017

PubMed Abstract: Brighter near-infrared (NIR) fluorescent proteins (FPs) are required for multicolor microscopy and deep-tissue imaging. Here, we present structural and biochemical analyses of three monomeric, spectrally distinct phytochrome-based NIR FPs, termed miRFPs. The miRFPs are closely related and differ by only a few amino acids, which define their molecular brightness, brightness in mammalian cells, and spectral properties. We have identified the residues responsible for the spectral red-shift, revealed a new chromophore bound simultaneously to two cysteine residues in the PAS and GAF domains in blue-shifted NIR FPs, and uncovered the importance of amino acid residues in the N-terminus of NIR FPs for their molecular and cellular brightness. The novel chromophore covalently links the N-terminus of NIR FPs with their C-terminal GAF domain, forming a topologically closed knot in the structure, and also contributes to the increased brightness. Based on our studies, we suggest a strategy to develop spectrally distinct NIR FPs with enhanced brightness.

PubMed: 28936332
DOI: 10.1039/c7sc00855d

Experimental method

X-RAY DIFFRACTION (1.35 Å)