Article

The protein Hrb57A of Drosophila melanogaster closely related to hnRNP K from vertebrates is present at sites active in transcription and coprecipitates with four RNA-binding proteins.

Fakultaet fuer Chemie AG,. Molekulare Zellbiochemie, Ruhr-Universitaet, Bochum, Germany.
Gene (impact factor: 2.34). 04/2000; 245(1):127-37. DOI:10.1016/S0378-1119(00)00027-5 pp.127-37
Source: PubMed

ABSTRACT The hnRNP K protein is among the major hnRNA-binding proteins with a strong preference for cytidine-rich sequences. We have cloned a Drosophila hnRNP protein closely related to this vertebrate protein. The protein first identified by the monoclonal antibody Q18 is encoded by a gene located in 57A on polytene chromosomes and has been consequently named Hrb57A. The amino acid sequence of the Hrb57A KH domains and their overall organisation in the protein are remarkably similar to the vertebrate proteins. As the hnRNP K in vertebrates the M(r) 55 000 Drosophila Hrb57A/Q18 protein strongly binds to poly(C) in vitro and is ubiquitously present in nuclei active in transcription. On polytene chromosomes it is found in many puffs and minipuffs. Hrb57A/Q18 specifically coprecipitates four other proteins: Hrb87F/P11 a Drosophila hnRNP A1 homologue, the hnRNA-binding protein S5, the RNA recognition motif-containing protein NonA and the RNA-binding zinc finger-containing protein on ecdysone puffs PEP/X4.

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Keywords

amino acid sequence
 
cytidine-rich sequences
 
Drosophila hnRNP A1 homologue
 
Drosophila hnRNP protein
 
ecdysone puffs PEP/X4
 
hnRNA-binding protein S5
 
hnRNP K
 
hnRNP K protein
 
Hrb57A KH domains
 
major hnRNA-binding proteins
 
minipuffs
 
nuclei active
 
polytene chromosomes
 
protein first
 
RNA recognition motif-containing protein NonA
 
RNA-binding zinc finger-containing protein
 
strong preference
 
vertebrate protein
 
vertebrate proteins
 
vertebrates
 

B T Hovemann