J Biol Chem, Vol. 274, Issue 6, 3503-3512, February 5, 1999
The Structure of the Site on Adenovirus Early Region 1A
Responsible for Binding to TATA-binding Protein Determined by NMR
Spectroscopy
David P.
Molloy
,
K. John
Smith§,
Anne E.
Milner
,
Phillip H.
Gallimore
, and
Roger J. A.
Grand
From the
CRC Institute for Cancer Studies, University
of Birmingham, Edgbaston, Birmingham B15 2TA, United Kingdom and
§ School of Biochemistry, University of Birmingham,
Edgbaston, Birmingham B15 2TT, United Kingdom
Previous detailed mutational analysis has shown
that the binding site on adenovirus (Ad) early region 1A (E1A) for
TATA-binding protein (TBP) is located toward the N terminus of
conserved region 3 (CR3). Here we demonstrate that synthetic peptides
of between 15 and 22 amino acids, identical to amino acid sequences of
CR3 present in the larger Ad5 E1A (13 S product) and in both the Ad12 E1A (13 and 12 S products) proteins that lie N-terminal to the zinc
finger motif, can disrupt binding of E1A to TBP. These findings suggest
that the peptides are biologically active in terms of interacting with
TBP and must therefore comprise some, if not all, of the TBP binding
site on E1A. The interaction between Ad12 E1A and TBP was confirmed by
direct co-precipitation experiments. In 1H NMR
studies of CR3 peptides, regular patterns of NOEs were observed from
which their conformational preferences in aqueous solution were
determined. Both Ad5 and Ad12 peptides were shown to contain regions of
helical backbone structure in 50% trifluoroethanol. In each case, the
type and intensities of NOE cross-peaks observed correlated best to
-helical turns. These helices are more extensive in larger peptides
and extend from Glu141 to Val147 and from
Arg144 to Pro152 in the full-length Ad5 and
Ad12 13S E1A proteins, respectively. The structure of a 19-residue Ad5
CR3 peptide carrying the V147L mutation in the full-length protein that
abolishes TBP binding was examined. No significant differences between
the substituted and wild type peptides were observed, suggesting that
this substitution in the intact protein may cause disruption of global
rather than local structures.
Copyright © 1999 by The American Society for Biochemistry and Molecular Biology, Inc.