Two versions of the gene encoding the 41-kilodalton subunit of the telomere binding protein of Oxytricha nova.
Macronuclear chromosomes of the ciliated protozoan Oxytricha nova terminate with a single-stranded (T4G4)2 overhang. The (T4G4)2 telomeric overhang is tenaciously bound by a protein heterodimer. We have cloned and sequenced the gene encoding the 41-kDa subunit of this telomere binding protein. The predicted amino acid sequence comprises two distinct regions, a carboxyl-terminal two-thirds that is 23% lysine and bears similarity to histone H1 and an amino-terminal one-third containing a hydrophobic stretch of about 15 amino acids. Two macronuclear versions of the gene differ in nucleotide sequence at several positions, but the derived polypeptides differ only at a single position, Ser-110 or Ala-110. Both versions harbor a small intron. The existence of this intron demonstrates that, despite the elimination of 95% of the micronuclear genome from the developing macronucleus, at least some noncoding DNA is retained during macronuclear development of hypotrichous ciliates.
Hicke
B J
BJ
Department of Molecular, Cellular and Developmental Biology, Howard Hughes Medical Institute, University of Colorado, Boulder 80309.
Celander
D W
DW
MacDonald
G H
GH
Price
C M
CM
Cech
T R
TR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016798:Ciliophora / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification; D005784:Gene Amplification; D015723:Gene Library; D005796:Genes; D007256:Information Systems; D007438:Introns; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010449:Peptide Mapping; D011487:Protein Conformation; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D012313:RNA; D004247:DNA