creators_name: Kaur, Gurmeet
creators_name: Subramanian, Srikrishna
type: article
datestamp: 2016-01-29 03:50:35
lastmod: 2016-01-29 03:50:35
metadata_visibility: show
title: The Ku-Mar zinc finger: A segment-swapped zinc ribbon in MarR-like transcription regulators related to the Ku bridge.
ispublished: pub
subjects: QR
keywords: Zinc ribbon; 
Segment-swapping; 
DNA-binding proteins; 
Helix-turn-helix domain; 
Dimerization; 
Multidrug resistance

note: Copyright of this article belongs to Elsevier Science.
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.
date: 2015-09
date_type: published
publication: Journal of structural biology
volume: 191
number: 3
publisher: Elsevier Science
pagerange: 281-9
refereed: TRUE
issn: 1095-8657
official_url: http://www.sciencedirect.com/science/article/pii/S1047847715300368
citation:   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