GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10924141

From GONUTS
Jump to: navigation, search
Citation

Spedaliere, CJ, Hamilton, CS and Mueller, EG (2000) Functional importance of motif I of pseudouridine synthases: mutagenesis of aligned lysine and proline residues. Biochemistry 39:9459-65

Abstract

On the basis of sequence alignments, the pseudouridine synthases were grouped into four families that share no statistically significant global sequence similarity, though some common sequence motifs were discovered [Koonin, E. V. (1996) Nucleic Acids. Res. 24, 2411-2415; Gustafsson, C., Reid, R., Greene, P. J., and Santi, D. V. (1996) Nucleic Acids Res. 24, 3756-3762]. We have investigated the functional significance of these alignments by substituting the nearly invariant lysine and proline residues in Motif I of RluA and TruB, pseudouridine synthases belonging to different families. Contrary to our expectations, the altered enzymes display only very mild kinetic impairment. Substitution of the aligned lysine and proline residues does, however, reduce structural stability, consistent with a temperature sensitive phenotype that results from substitution of the cognate proline residue in Cbf5p, a yeast homologue of TruB [Zerbarjadian, Y., King, T., Fournier, M. J., Clarke, L., and Carbon, J. (1999) Mol. Cell. Biol. 19, 7461-7472]. Together, our data support a functional role for Motif I, as predicted by sequence alignments, though the effect of substituting the highly conserved residues was milder than we anticipated. By extrapolation, our findings also support the assignment of pseudouridine synthase function to certain physiologically important eukaryotic proteins that contain Motif I, including the human protein dyskerin, alteration of which leads to the disease dyskeratosis congenita.

Links

PubMed

Keywords

Amino Acid Motifs/genetics; Circular Dichroism; Escherichia coli/enzymology; Escherichia coli/genetics; Hot Temperature; Hydro-Lyases/chemistry; Hydro-Lyases/genetics; Hydro-Lyases/isolation & purification; Kinetics; Lysine/chemistry; Lysine/genetics; Multigene Family; Mutagenesis, Site-Directed; Proline/chemistry; Proline/genetics; Sequence Alignment; Sequence Homology, Amino Acid

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status


See also

References

See Help:References for how to manage references in GONUTS.