8VRH

E. coli peptidyl-prolyl cis-trans isomerase containing delta2-monofluoro-leucines

This is a non-PDB format compatible entry.

Summary for 8VRH

• Entry DOI: 10.2210/pdb8vrh/pdb
• Descriptor: Peptidyl-prolyl cis-trans isomerase B, 1,2-ETHANEDIOL, TRIETHYLENE GLYCOL, ... (7 entities in total)
• Functional Keywords: peptidyl-prolyl cis-trans isomerase, non-canonical amino acids, fluorinated leucine, isomerase
• Biological source: Escherichia coli
• Total number of polymer chains: 4
• Total formula weight: 74707.40

Authors

Frkic, R.L.,Jackson, C.J. (deposition date: 2024-01-22, release date: 2024-05-22, Last modification date: 2024-06-19)

Primary citation

Frkic, R.L.,Tan, Y.J.,Abdelkader, E.H.,Maleckis, A.,Tarcoveanu, E.,Nitsche, C.,Otting, G.,Jackson, C.J.
Conformational Preferences of the Non-Canonical Amino Acids (2 S ,4 S )-5-Fluoroleucine, (2 S ,4 R )-5-Fluoroleucine, and 5,5'-Difluoroleucine in a Protein.
Biochemistry, 63:1388-1394, 2024

PubMed Abstract: Proteins produced with leucine analogues, where CHF groups substitute specific methyl groups, can readily be probed by F NMR spectroscopy. As CF and CH groups are similar in hydrophobicity and size, fluorinated leucines are expected to cause minimal structural perturbation, but the impact of fluorine on the rotational freedom of CHF groups is unclear. We present high-resolution crystal structures of peptidyl-prolyl - isomerase B (PpiB) prepared with uniform high-level substitution of leucine by (2,4)-5-fluoroleucine, (2,4)-5-fluoroleucine, or 5,5'-difluoroleucine. Apart from the fluorinated leucine residues, the structures show complete structural conservation of the protein backbone and the amino acid side chains except for a single isoleucine side chain located next to a fluorine atom in the hydrophobic core of the protein. The carbon skeletons of the fluorinated leucine side chains are also mostly conserved. The CHF groups show a strong preference for staggered rotamers and often appear locked into single rotamers. Substitution of leucine CH groups for CHF groups is thus readily tolerated in the three-dimensional (3D) structure of a protein, and the rotation of CHF groups can be halted at cryogenic temperatures.

PubMed: 38742763
DOI: 10.1021/acs.biochem.4c00081

Experimental method

X-RAY DIFFRACTION (1.8 Å)