Linked Life Data

7723029

Source:http://linkedlifedata.com/resource/pubmed/id/7723029

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-5-25
pubmed:abstractText
The bacteriophage Mu Com protein is a small "zinc finger-like" protein that binds a specific site in com-mom operon mRNA and activates translation of the mom open-reading-frame. Com contains six cysteine and five histidine residues that have the potential to form several alternative zinc-finger-like motifs. We have used oligonucleotide site-directed mutagenesis to individually alter each of these amino acids (Cys to Ser, and His to Asn or Gln) and tested the various forms of Com for their ability to function in vivo. We observed that mutation of any one of the four N-terminal cysteine residues (Cys-6, 9, 26 or 29) resulted in loss of Com activity. The Com protein requires zinc in order to fold into its functional tertiary structure, as demonstrated by characteristic 1H nuclear magnetic resonance (NMR) chemical shifts. 1H chemical shifts revert to random coil values in the presence of the metal chelator EDTA. The metal-binding specificity and thermal stability of Com also has been investigated using 1H NMR. We report the use of 113Cd NMR, 1H-113Cd heteronuclear spin-echo difference spectroscopy HSED and Zn extended X-ray absorption fine structure spectroscopy EXAFS to determine the zinc/protein stoichiometry as 1:1 and the ligand environment as tetrathiolate. Comparative NMR spectra of Com mutants C6S and C39S suggest position 6 is involved in zinc coordination, while position 39 is not metal-liganded. These studies indicate that the metal coordination, site of Com is a four-cysteine complex, involving residues 6, 9, 26 and 29.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
247
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
753-64
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The zinc coordination site of the bacteriophage Mu translational activator protein, Com.
pubmed:affiliation
Department of Chemistry, University of Rochester, NY 14627, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.