PMID- 10504263
OWN - NLM
STAT- MEDLINE
DCOM- 19991020
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 38
IP  - 39
DP  - 1999 Sep 28
TI  - MRE-Binding transcription factor-1: weak zinc-binding finger domains 5 and 6
      modulate the structure, affinity, and specificity of the metal-response element
      complex.
PG  - 12915-25
AB  - MRE-binding transcription factor-1 (MTF-1) contains six Cys(2)-His(2) zinc finger
      sequences, and it has been suggested that the zinc finger domain itself may
      function as a zinc sensor in zinc-activated expression of metallothioneins (MTs).
      Previous work has shown that a subset ( approximately 3-4) of the zinc fingers in
      MTF-zf play a structural role in folding and high-affinity metal-response element
      (MREd) binding, while one or more other fingers have properties consistent with a
      metalloregulatory role (weak zinc binding affinity in the absence of DNA). We
      show here that zinc fingers 5 and 6 correspond to the weak zinc-binding fingers
      in MTF-zf. Limited trypsinolysis of a Zn(6)-MTF-zf:MREd complex gives rise to a
      highly protease-resistant core fragment corresponding to amino acids 137-260 or
      N-terminal zinc fingers 1-4 of MTF-zf. Characterization of a collection of
      broken-finger (His --> Asn) and missing-finger mutants of MTF-zf reveals that
      deletion of zinc fingers 5 and 6 to create MTF-zf14 attenuates MREd binding
      affinity ( approximately 20-fold), while deletion of fingers 4-6 (MTF-zf13)
      results in a further 20-fold reduction of binding affinity with a nearly complete
      loss of specificity. Circular dichroism studies reveal that the binding of MTF-zf
      to the MREd induces a dramatic alteration of the structure of the MREd from a
      B-form to a double-helical conformation with A-like features. Formation of
      stoichiometric complexes with MTF-zf14, H279N (Deltazf5) MTF-zf, and MTF-zf13
      induces comparatively less A-like structure. Steady-state fluorescence resonance 
      energy transfer (FRET) spectroscopy has been used to globally define the
      orientation of the multifinger MTF-zf on the MREd. These experiments suggest that
      fingers 1-4 are oriented on the highly conserved TGCRCnC side of the MREd with
      fingers 5-6 bound at or near the gGCCc sequence. These findings are consistent
      with a model in which the N-terminal zinc fingers in MTF-zf are required for high
      affinity and specific binding to the consensus TGCRCnC core in a way which is
      subjected to structural and allosteric modulation by the weak zinc-binding
      C-terminal zinc fingers.
FAU - Chen, X
AU  - Chen X
AD  - Department of Biochemistry and Biophysics, Center for Macromolecular Design,
      Texas A&M University, College Station, Texas 77843-2128, USA.
FAU - Chu, M
AU  - Chu M
FAU - Giedroc, D P
AU  - Giedroc DP
LA  - eng
GR  - GM42569/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (DNA-Binding Proteins)
RN  - 0 (Recombinant Proteins)
RN  - 0 (Transcription Factors)
RN  - 0 (transcription factor MTF-1)
RN  - 9007-49-2 (DNA)
RN  - EC 3.4.21.4 (Trypsin)
SB  - IM
MH  - Amino Acid Sequence
MH  - Base Sequence
MH  - Circular Dichroism
MH  - DNA
MH  - DNA-Binding Proteins
MH  - Energy Transfer
MH  - Hydrolysis
MH  - Molecular Sequence Data
MH  - Mutagenesis
MH  - Recombinant Proteins/chemistry/isolation & purification/metabolism
MH  - Spectrometry, Fluorescence
MH  - Spectrophotometry, Ultraviolet
MH  - Structure-Activity Relationship
MH  - Transcription Factors/chemistry/isolation & purification/*metabolism
MH  - Trypsin/metabolism
MH  - *Zinc Fingers
EDAT- 1999/10/03 00:00
MHDA- 1999/10/03 00:01
CRDT- 1999/10/03 00:00
PHST- 1999/10/03 00:00 [pubmed]
PHST- 1999/10/03 00:01 [medline]
PHST- 1999/10/03 00:00 [entrez]
AID - bi9913000 [pii]
AID - 10.1021/bi9913000 [doi]
PST - ppublish
SO  - Biochemistry. 1999 Sep 28;38(39):12915-25. doi: 10.1021/bi9913000.