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The structural role of the zinc ion can be dispensable in prokaryotic zinc-finger domains

TitoloThe structural role of the zinc ion can be dispensable in prokaryotic zinc-finger domains
Tipo di pubblicazioneArticolo su Rivista peer-reviewed
Anno di Pubblicazione2009
AutoriBaglivo, I., Russo L., Esposito S., Malgieri G., Renda M., Salluzzo Antonio, Di Blasio B., Isernia C., Fattorusso R., and Pedone P.V.
RivistaProceedings of the National Academy of Sciences of the United States of America
Volume106
Paginazione6933-6938
ISSN00278424
Parole chiaveAgrobacterium, Alphaproteobacteria, Amino Acid, Amino Acid Sequence, amino acid substitution, article, aspartic acid, bacterial protein, Bacterial Proteins, binding affinity, Biomolecular, cation, Cations, chemistry, Cysteine, data base, DNA binding, Eukaryota, eukaryote, gene transfer, genetics, Hydrophobicity, Mass Spectrometry, Mesorhizobium, Mesorhizobium loti, metabolism, molecular genetics, Molecular Sequence Data, mutant, nonhuman, Nuclear magnetic resonance, nucleotide sequence, point mutation, priority journal, Prokaryota, prokaryote, protein binding, protein derivative, protein secondary structure, Protein Structure, Ros protein, Secondary, Sequence Alignment, sequence homology, structure analysis, unclassified drug, Zinc, zinc finger motif, zinc finger protein, Zinc Fingers, zinc ion
Abstract

The recent characterization of the prokaryotic Cys2His 2 zinc-finger domain, identified in Ros protein from Agrobacterium tumefa-ciens, has demonstrated that, although possessing a similar zinc coordination sphere, this domain is structurally very different from its eukaryotic counterpart. A search in the databases has identified ≈300 homologues with a high sequence identity to the Ros protein, including the amino acids that form the extensive hydrophobic core in Ros. Surprisingly, the Cys2His2 zinc coordination sphere is generally poorly conserved in the Ros homologues, raising the question of whether the zinc ion is always preserved in these proteins. Here, we present a functional and structural study of a point mutant of Ros protein, Ros56-142C82D, in which the second coordinating cysteine is replaced by an aspartate, 5 previ-ously-uncharacterized representative Ros homologues from Me-sorhizobium loti, and 2 mutants of the homologues. Our results indicate that the prokaryotic zinc-finger domain, which in Ros protein tetrahedrally coordinates Zn(ll) through the typical Cys 2His2 coordination, in Ros homologues can either exploit a CysAspHis2 coordination sphere, previously never described in DNA binding zinc finger domains to our knowledge, or lose the metal, while still preserving the DNA-binding activity. We demonstrate that this class of prokaryotic zinc-finger domains is structurally very adaptable, and surprisingly single mutations can transform a zinc-binding domain into a nonzinc-binding domain and vice versa, without affecting the DNA-binding ability. In light of our findings an evolutionary link between the prokaryotic and eukaryotic zinc-finger domains, based on bacteria-to-eukaryota horizontal gene transfer, is discussed.

Note

cited By 22

URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-66349098084&doi=10.1073%2fpnas.0810003106&partnerID=40&md5=50a54153c74a3447019d9192a4afa97f
DOI10.1073/pnas.0810003106
Citation KeyBaglivo20096933