6DMX

HBZ56 in complex with KIX and c-Myb


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.242 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural basis for cooperative regulation of KIX-mediated transcription pathways by the HTLV-1 HBZ activation domain.

Yang, K.Stanfield, R.L.Martinez-Yamout, M.A.Dyson, H.J.Wilson, I.A.Wright, P.E.

(2018) Proc Natl Acad Sci U S A 115: 10040-10045

  • DOI: 10.1073/pnas.1810397115
  • Primary Citation of Related Structures:  
    6DMX, 6DNQ

  • PubMed Abstract: 
  • The human T cell leukemia virus I basic leucine zipper protein (HTLV-1 HBZ) maintains chronic viral infection and promotes leukemogenesis through poorly understood mechanisms involving interactions with the KIX domain of the transcriptional coactivator CBP and its paralog p300 ...

    The human T cell leukemia virus I basic leucine zipper protein (HTLV-1 HBZ) maintains chronic viral infection and promotes leukemogenesis through poorly understood mechanisms involving interactions with the KIX domain of the transcriptional coactivator CBP and its paralog p300. The KIX domain binds regulatory proteins at the distinct MLL and c-Myb/pKID sites to form binary or ternary complexes. The intrinsically disordered N-terminal activation domain of HBZ (HBZ AD) deregulates cellular signaling pathways by competing directly with cellular and viral transcription factors for binding to the MLL site and by allosterically perturbing binding of the transactivation domain of the hematopoietic transcription factor c-Myb. Crystal structures of the ternary KIX:c-Myb:HBZ complex show that the HBZ AD recruits two KIX:c-Myb entities through tandem amphipathic motifs (L/V)(V/L)DGLL and folds into a long α-helix upon binding. Isothermal titration calorimetry reveals strong cooperativity in binding of the c-Myb activation domain to the KIX:HBZ complex and in binding of HBZ to the KIX:c-Myb complex. In addition, binding of KIX to the two HBZ (V/L)DGLL motifs is cooperative; the structures suggest that this cooperativity is achieved through propagation of the HBZ α-helix beyond the first binding motif. Our study suggests that the unique structural flexibility and the multiple interaction motifs of the intrinsically disordered HBZ AD are responsible for its potency in hijacking KIX-mediated transcription pathways. The KIX:c-Myb:HBZ complex provides an example of cooperative stabilization in a transcription factor:coactivator network and gives insights into potential mechanisms through which HBZ dysregulates hematopoietic transcriptional programs and promotes T cell proliferation.


    Organizational Affiliation

    The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
BZIP factorA [auth E], F [auth J]58Human T-cell leukemia virus type IMutation(s): 2 
Gene Names: HBZ
Find proteins for P0C746 (Human T-cell leukemia virus 1 (strain Japan ATK-1 subtype A))
Explore P0C746 
Go to UniProtKB:  P0C746
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Transcriptional activator MybD [auth A], B [auth C], I [auth F], G [auth H]32Mus musculusMutation(s): 0 
Gene Names: Myb
Find proteins for P06876 (Mus musculus)
Explore P06876 
Go to UniProtKB:  P06876
NIH Common Fund Data Resources
IMPC:  MGI:97249
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
CREB-binding proteinE [auth B], C [auth D], J [auth G], H [auth I]88Mus musculusMutation(s): 0 
Gene Names: CrebbpCbp
EC: 2.3.1.48 (PDB Primary Data), 2.3.1 (UniProt)
Find proteins for P45481 (Mus musculus)
Explore P45481 
Go to UniProtKB:  P45481
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.242 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.997α = 90
b = 80.311β = 92.6
c = 64.641γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)United StatesCA214054

Revision History  (Full details and data files)

  • Version 1.0: 2018-09-19
    Type: Initial release
  • Version 1.1: 2018-10-03
    Changes: Data collection, Database references
  • Version 1.2: 2018-10-17
    Changes: Data collection, Database references
  • Version 1.3: 2019-12-18
    Changes: Author supporting evidence