Unnatural amino acid replacement in a yeast G protein-coupled receptor in its native environment.

Huang, LY
Umanah, G
Hauser, M
Son, Çağdaş Devrim
Arshava, B
Naider, F
Becker, JM
Ste2p is the G protein-coupled receptor (GPCR) for the tridecapeptide pheromone cc factor of Saccharomyces cerevisiae. This receptor- pheromone pair has been used extensively as a paradigm for investigating GPCR structure and function. Expression in yeast harboring a cognate tRNA/aminoacyl-tRNA synthetase pair specifically evolved to incorporate p-benzoyl-L-phenylalanine (Bpa) in response to the amber codon allowed the biosynthesis of Bpa-substituted Ste2p in its native cell. We replaced natural amino acid residues in Ste2p with Bpa by engineering amber TAG stop codons into STE2 encoded on a plasmid. Several of the expressed Bpa-substituted Ste2p receptors exhibited high-affinity ligand binding, and incorporation of Bpa into Ste2p influenced biological activity as measured by growth arrest of whole cells in response to cc factor. We found that, at concentrations of 0.1-0.5 mM, a dipeptide containing Bpa could be used to enhance delivery of Bpa into the cell, while at 2 mM, both dipeptide and Bpa were equally effective. The application of a peptide delivery system for unnatural amino acids will extend the use of the unnatural amino acid replacement methodology to amino acids that are impermeable to yeast. Incorporation of Bpa into Ste2p was verified by mass spectrometric analysis, and two Bpa-Ste2p mutants were able to selectively capture a factor into the ligand-binding site after photoactivation. To our knowledge, this is the first experimental evidence documenting an unnatural amino acid replacement in a GPCR expressed in its native environment and the use of a mutated receptor to photocapture a peptide ligand.


Sequences in the intracellular loops of the yeast pheromone receptor Ste2p required for G protein activation.
Celić, A; Martin, NP; Son, Çağdaş Devrim; Becker, JM; Naider, F; Dumont, ME (American Chemical Society (ACS), 2003-03-18)
The α-factor receptor of the yeast Saccharomyces cerevisiae encoded by the STE2 gene is a member of the large family of G protein-coupled receptors (GPCRs) that mediate multiple signal transduction pathways. The third intracellular loop of GPCRs has been identified as a likely site of interaction with G proteins. To determine the extent of allowed substitutions within this loop, we subjected a stretch of 21 amino acids (Leu228−Leu248) to intensive random mutagenesis and screened multiply substituted alleles...
KOCABIVIK, S; PERLIN, MH (Elsevier BV, 1994-01-01)
1. Oligonucleotide-directed mutagenesis of APH(3')-II was used to investigate the functions of key amino acids in the P-loop analogous motif of the enzyme. 2. The mutations of Gly205 --> GIu, Gly210 --> Ala and Arg211 --> Pro considerably reduced the resistance of the resulting strains to KM and to related drugs, e.g. G418. 3. Similarly, enzyme activity in the crude extracts of these mutants was substantially reduced as well as the enzyme's affinity for Mg2+ ATP. 4. Alternatively substitutions at a highly c...
Benzaldehyde lyase from pseudomonas fluorescens biovar i mediated biotransformation for the synthesis of chiral alpha hydroxy ketones
Hoşrik, Birsu Semra; Demir, Ayhan Sıtkı; Department of Biochemistry (2010)
Optically active α-hydroxy ketones are important subunits of many biologically active compounds and indispensable synthons for asymmetric synthesis. Benzaldehyde Lyase from Pseudomonas fluorescens Biovar I is a novel ThDP-dependent enzyme that catalyzes the synthesis of benzoin type chiral α-hydroxy ketones starting from both benzaldehyde and racemic benzoin derivatives. Benzaldehyde Lyase is the first example of enzymes in the literature which leads to a chemical resolution of enantiomers of benzoin deriva...
Isolation and immunological characterization of theta class glutathione-s-transferase gstt2-2 from bovine liver
İşgör, Sultan Belgin; Çoruh, Nursen; Department of Biochemistry (2004)
The glutathione-S-transferases (GSTs) (EC. are enzymes that participate in cellular detoxification of endogenous as well as foreign electrophilic compounds, function in the cellular detoxification systems and are evolved to protect cells against reactive oxygen metabolites by conjugating the reactive molecules to the nucleophile scavenging tripeptide glutathione (GSH, ?-glu-cys-gly). The GSTs are found in all eukaryotes and prokaryotic systems, in the cytoplasm, on the microsomes, and in the mitoch...
Cross-Linking of a DOPA-Containing Peptide Ligand into its G Protein-Coupled Receptor
Umanah, George E.; Son, Çağdaş Devrim; Ding, FaXiang; Naider, Fred; Becker, Jeffrey M. (American Chemical Society (ACS), 2009-04-01)
The interaction between a 3,4-dihydroxylphenylalanine (DOPA) labeled analog of the tridecapeptide α-factor (W-H-W-L-Q-L-K-P-G-Q-P-M-Y) and Ste2p, a Saccharomyces cerevisiae model G protein-coupled receptor (GPCR), has been analyzed by periodate-mediated cross-linking. Chemically synthesized α-factor with DOPA substituting for tyrosine at position 13 and biotin tagged onto lysine7 ([Lys7 (BioACA),-Nle12,DOPA13]α-factor; Bio-DOPA-α-factor) was used for crosslinking into Ste2p. The biological activity of Bio-D...
Citation Formats
L. Huang et al., “Unnatural amino acid replacement in a yeast G protein-coupled receptor in its native environment.,” Biochemistry, pp. 5638–48, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/43054.