Abstract
Two different type II topoisomerases are known in bacteria. DNA gyrase (Gyr) introduces negative supercoils into DNA. Topoisomerase IV (Par) relaxes DNA supercoils. GyrA and ParC subunits of bacterial type II topoisomerases are involved in breakage and reunion of DNA. The spatial structure of the C-terminal fragment in GyrA/ParC is not available. We infer homology between the C-terminal domain of GyrA/ParC and a regulator of chromosome condensation (RCC1), a eukaryotic protein that functions as a guanine-nucleotide-exchange factor for the nuclear G protein Ran. This homology, complemented by detection of 6 sequence repeats with 4 predicted β-strands each in GyrA/ParC sequences, allows us to predict that the GyrA/ParC C-terminal domain folds into a 6-bladed β-propeller. The prediction rationalizes available experimental data and sheds light on the spatial properties of the largest topoisomerase domain that lacks structural information.
Original language | English (US) |
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Pages (from-to) | 258-264 |
Number of pages | 7 |
Journal | Proteins: Structure, Function and Genetics |
Volume | 47 |
Issue number | 3 |
DOIs | |
State | Published - May 15 2002 |
Keywords
- GyrA
- Non specific DNA binding
- ParC
- Regulator of chromosome condensation
- Remote homology detection
- Topoisomerase
ASJC Scopus subject areas
- Structural Biology
- Biochemistry
- Molecular Biology