Genomic expansion and clustering of ZAD-containing C2H2 zinc-finger genes in Drosophila.
C2H2 zinc-finger proteins (ZFPs) constitute the largest family of nucleic acid binding factors in higher eukaryotes. In silico analysis identified a total of 326 putative ZFP genes in the Drosophila genome, corresponding to approximately 2.3% of the annotated genes. Approximately 29% of the Drosophila ZFPs are evolutionary conserved in humans and/or Caenorhabditis elegans. In addition, approximately 28% of the ZFPs contain an N-terminal zinc-finger-associated C4DM domain (ZAD) consisting of approximately 75 amino acid residues. The ZAD is restricted to ZFPs of dipteran and closely related insects. The evolutionary restriction, an expansion of ZAD-containing ZFP genes in the Drosophila genome and their clustering at few chromosomal sites are features reminiscent of vertebrate KRAB-ZFPs. ZADs are likely to represent protein-protein interaction domains. We propose that ZAD-containing ZFP genes participate in transcriptional regulation either directly or through site-specific modification and/or regulation of chromatin.
Chung
Ho-Ryun
HR
Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Am Fassberg, D-37077 Göttingen, Germany.
Schäfer
Ulrich
U
Jäckle
Herbert
H
Böhm
Siegfried
S
D000595:Amino Acid Sequence; D000818:Animals; D004330:Drosophila / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome; D007438:Introns; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D017434:Protein Structure, Tertiary / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D016335:Zinc Fingers / Q000235:genetics* / Q000502:physiology