The following proteins, which seems to belong to a family of pseudouridine synthases (EC 5.4.99.-) [1] have been shown to share regions of similarities:

• Escherichia coli and Haemophilus influenzae ribosomal large subunit pseudouridine synthase A (gene rluA). It is responsible for synthesis of pseudouridine from uracil-746 IN 23S rRNA.
• Escherichia coli and Haemophilus influenzae ribosomal large subunit pseudouridine synthase C (gene rluC). It is responsible for synthesis of pseudouridine from uracil at positions 955, 2504 and 2580 in 23S rRNA.
• Escherichia coli protein and homologs in other bacteria large subunit pseudouridine synthase D (gene rluD).
• Yeast DRAP deaminase (gene RIB2).
• Escherichia coli and Haemophilus influenzae tRNA pseudouridine synthase C (truC).
• Haemophilus influenzae hypothetical protein HI0042.
• Aquifex aeolicus hypothetical protein AQ_1758.
• Bacillus subtilis hypothetical protein yhcT.
• Bacillus subtilis hypothetical protein yjbO.
• Bacillus subtilis hypothetical protein ylyB.
• Helicobacter pylori hypothetical protein HP0347.
• Helicobacter pylori hypothetical protein HP0745.
• Helicobacter pylori hypothetical protein HP0956.
• Mycoplasma genitalium hypothetical protein MG209.
• Mycoplasma genitalium hypothetical protein MG370.
• Synechocystis strain PCC 6803 hypothetical protein slr1592.
• Synechocystis strain PCC 6803 hypothetical protein slr1629.
• Yeast hypothetical protein YDL036c.
• Yeast hypothetical protein YGR169c.
• Fission yeast hypothetical protein SpAC18B11.02c.
• Caenorhabditis elegans hypothetical protein K07E8.7.

These are proteins of from 21 to 50 Kd which contain a number of conserved regions in their central section. They can be picked up in the database by the following highly conserved pattern.