4GLJ: Crystal structure of methylthioadenosine phosphorylase in complex with rhodamine B

Citation:
Abstract
The presented study examines the phenomenon of the fluorescence under UV light excitation (312 nm) of E. coli cells expressing a novel metagenomic-derived putative methylthioadenosine phosphorylase gene, called rsfp, grown on LB agar supplemented with a fluorescent dye rhodamine B. For this purpose, an rsfp gene was cloned and expressed in an LMG194 E. coli strain using an arabinose promoter. The resulting RSFP protein was purified and its UV-VIS absorbance spectrum and emission spectrum were assayed. Simultaneously, the same spectroscopic studies were carried out for rhodamine B in the absence or presence of RSFP protein or native E. coli proteins, respectively. The results of the spectroscopic studies suggested that the fluorescence of E. coli cells expressing rsfp gene under UV illumination is due to the interaction of rhodamine B molecules with the RSFP protein. Finally, this interaction was proved by a crystallographic study and then by site-directed mutagenesis of rsfp gene sequence. The crystal structures of RSFP apo form (1.98 A) and complex RSFP/RB (1.90 A) show a trimer of RSFP molecules located on the crystallographic six fold screw axis. The RSFP complex with rhodamine B revealed the binding site for RB, in the pocket located on the interface between symmetry related monomers.
PDB ID: 4GLJDownload
MMDB ID: 107749
PDB Deposition Date: 2012/8/14
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 4GLJ: trimeric; determined by author and by software (PISA)
Molecular Components in 4GLJ
Label Count Molecule
Proteins (3 molecules)
3
Rsfp
Molecule annotation
Chemicals (12 molecules)
1
6
2
3
3
3
* Click molecule labels to explore molecular sequence information.

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