Molecular cloning and expression of a Tetrahymena pyriformis ubiquitin fusion gene coding for a 53-amino-acid extension protein

✍ Scribed by Neves, Ana M. ;Guerreiro, Paulo ;Miquerol, Lucile ;Rodrigues-Pousada, Claudina

• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 873 KB
• Volume: 230
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00290667

✦ Synopsis

The genome of Tetrahymena pyriformis has been shown to contain a ubiquitin multigene family consisting of several polyubiquitin genes and at least one ubiquitin fusion gene. We report here the isolation and characterization of one genomic clone (pTU11), that encodes a ubiquitin extension protein. A comparison of the predicted amino acid sequence of the ubiquitin extension protein gene of T. pyriformis with those from other organisms indicated a high degree of homology. However, the Tetrahymena ubiquitin extension protein contains 53 and not 52 amino acids. This feature is different from all ubiquitin 52-amino-acid extension protein genes thus far sequenced. Furthermore, we found an array of four cysteine residues similar to those found in nucleic acid binding proteins. Also, the C-terminal sequence possesses a conserved motif which may represent a nuclear translocation signal. The ubiquitin 53-amino-acid extension protein gene encodes the smallest class of ubiquitin mRNAs in T. pyriformis.