Abstract:
:The Drosophila extra sex combs (esc) protein, a member of the Polycomb group (PcG), is a transcriptional repressor of homeotic genes. Genetic studies have shown that esc protein is required in early embryos at about the time that other PcG proteins become engaged in homeotic gene repression. The esc protein consists primarily of multiple copies of the WD repeat, a motif that has been implicated in protein-protein interaction. To further investigate the domain organization of esc protein, we have isolated and characterized esc homologs from divergent insect species. We report that esc protein is highly conserved in housefly (72% identical to Drosophila esc), butterfly (55% identical), and grasshopper (56% identical). We show that the butterfly homolog provides esc function in Drosophila, indicating that the sequence similarities reflect functional conservation. Homology modeling using the crystal structure of another WD repeat protein, the G-protein beta-subunit, predicts that esc protein adopts a beta-propeller structure. The sequence comparisons and modeling suggest that there are seven WD repeats in esc protein which together form a seven-bladed beta-propeller. We locate the conserved regions in esc protein with respect to this predicted structure. Site-directed mutagenesis of specific loops, predicted to extend from the propeller surface, identifies conserved parts of esc protein required for function in vivo. We suggest that these regions might mediate physical interaction with esc partner proteins.
journal_name
Mol Cell Bioljournal_title
Molecular and cellular biologyauthors
Ng J,Li R,Morgan K,Simon Jdoi
10.1128/mcb.17.11.6663subject
Has Abstractpub_date
1997-11-01 00:00:00pages
6663-72issue
11eissn
0270-7306issn
1098-5549journal_volume
17pub_type
杂志文章abstract::To interrogate genes essential for cell growth, proliferation and survival in human cells, we carried out a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 screen in a B-cell lymphoma line using a custom extended-knockout (EKO) library of 278,754 single-guide RNAs (sgRNAs) that targe...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
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journal_title:Molecular and cellular biology
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pub_type: 杂志文章
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更新日期:2000-01-01 00:00:00
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doi:10.1128/mcb.12.10.4601
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pub_type: 杂志文章
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更新日期:2005-04-01 00:00:00
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更新日期:2004-03-01 00:00:00