The lysine-rich C-terminal repeats of the centromere-binding factor 5 (Cbf5) of Kluyveromyces lactis are not essential for function.
The gene coding for the centromere-binding factor 5 (CBF5) of Kluyveromyces lactis has been isolated by hybridization of a Saccharomyces cerevisiae CBF5 DNA probe to a K. lactis library. The amino acid sequence of KlCbf5 is highly homologous, 88% identity, to ScCbf5, but also to the rat protein Nap57 (64% identity). The main difference between both yeast proteins and the rat protein is the presence of a lysine-rich domain with KKE/D repeats in the C-terminal part of the protein. These repeats are thought to be involved in binding of the protein to microtubules. Deletion of the KKE/D domain in KlCbf5 however, has no discernible effect on growth on rich medium, sensitivity to the microtubule-destabilizing drug benomyl or segregation of a reporter plasmid. On the other hand, insertion of two leucine residues adjacent to the KKE domain increases the loss rate of a reporter plasmid. In both yeasts complementation of a lethal CBF5 disruption with the heterologous gene results in a slight increase in benomyl sensitivity. A possible role of CBF5 in chromosome segregation will be discussed.
Winkler
A A
AA
Institute for Molecular Plant Sciences, Leiden, The Netherlands.
Bobok
A
A
Zonneveld
B J
BJ
Steensma
H Y
HY
Hooykaas
P J
PJ
D000595:Amino Acid Sequence; D000818:Animals; D001542:Benomyl / Q000494:pharmacology; D002503:Centromere / Q000378:metabolism; D005800:Genes, Fungal; D006836:Hydro-Lyases; D007716:Kluyveromyces / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D008239:Lysine / Q000737:chemistry; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D010957:Plasmids; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D051381:Rats; D015183:Restriction Mapping; D017411:Ribonucleoproteins, Small Nuclear; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D013045:Species Specificity; D013329:Structure-Activity Relationship; D014170:Transformation, Genetic
D008869:Microtubule-Associated Proteins; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D006836:Hydro-Lyases; C082278:CBF5 protein, S cerevisiae; D008239:Lysine; D001542:Benomyl