Kaur, Gurmeet and Subramanian, Srikrishna (2015) The Ku-Mar zinc finger: A segment-swapped zinc ribbon in MarR-like transcription regulators related to the Ku bridge. Journal of structural biology, 191 (3). pp. 281-9. ISSN 1095-8657
Full text not available from this repository. (Request a copy)Abstract
Two putative oxidative-stress sensor proteins from Pseudomonas aeruginosa, PA1607 and PA1374, belong to the MarR family of transcription regulators and possess a unique mode of dimerization. In these proteins, in addition to the α-helices involved in dimerization, inter-subunit contacts are strengthened by additional C-terminal β-strands. Using sequence and structure analysis we show that these β-strands constitute a novel segment-swapped zinc ribbon domain. We detect the presence of the zinc ribbon domain in MarR proteins from many bacterial homologs. While the metal-chelating residues of the zinc ribbons are absent in most members of this family, we could however identify several species of Proteobacteria, Actinobacteria and Firmicutes that possess intact zinc-chelating sites. Conservation pattern of metal-chelating residues together with the extensive structural resemblance to zinc ribbons, in particular to the bridge-region of the dsDNA break repair protein Ku, suggests that the C-terminal β-rich region of these proteins is a zinc ribbon. Sequence analysis also supports a distant evolutionary connection between the zinc ribbons of the MarR and Ku families. However, unlike Ku where the segment-swapped zinc ribbons play a role in DNA-binding and obligate dimerization, their primary role in MarR appears to be in dimerization and strengthening of inter-subunit contacts.
| Item Type: | Article |
|---|---|
| Additional Information: | Copyright of this article belongs to Elsevier Science. |
| Uncontrolled Keywords: | Zinc ribbon; Segment-swapping; DNA-binding proteins; Helix-turn-helix domain; Dimerization; Multidrug resistance |
| Subjects: | Q Science > QR Microbiology |
| Depositing User: | Dr. K.P.S.Sengar |
| Date Deposited: | 29 Jan 2016 03:50 |
| Last Modified: | 29 Jan 2016 03:50 |
| URI: | http://crdd.osdd.net/open/id/eprint/1761 |
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