2XJZ: Crystal Structure Of The Lmo2:ldb1-lid Complex, C2 Crystal Form

Citation:
Abstract
The LIM only protein 2 (LMO2) is a key regulator of hematopoietic stem cell development whose ectopic expression in T cells leads to the onset of acute lymphoblastic leukemia. Through its LIM domains, LMO2 is thought to function as the scaffold for a DNA-binding transcription regulator complex, including the basic helix-loop-helix proteins SCL/TAL1 and E47, the zinc finger protein GATA-1, and LIM-domain interacting protein LDB1. To understand the role of LMO2 in the formation of this complex and ultimately to dissect its function in normal and aberrant hematopoiesis, we solved the crystal structure of LMO2 in complex with the LID domain of LDB1 at 2.4 A resolution. We observe a largely unstructured LMO2 kept in register by the LID binding both LIM domains. Comparison of independently determined crystal structures of LMO2 reveals large movements around a conserved hinge between the LIM domains. We demonstrate that such conformational flexibility is necessary for binding of LMO2 to its partner protein SCL/TAL1 in vitro and for the function of this complex in vivo. These results, together with molecular docking and analysis of evolutionarily conserved residues, yield the first structural model of the DNA-binding complex containing LMO2, LDB1, SCL/TAL1, and GATA-1.
PDB ID: 2XJZDownload
MMDB ID: 83449
PDB Deposition Date: 2010/7/6
Updated in MMDB: 2017/07
Experimental Method:
x-ray diffraction
Resolution: 2.8  Å
Source Organism:
Similar Structures:
Biological Unit for 2XJZ: dimeric; determined by author and by software (PISA)
Molecular Components in 2XJZ
Label Count Molecule
Proteins (2 molecules)
1
Rhombotin-2(Gene symbol: LMO2)
Molecule annotation
1
LIM Domain-binding Protein 1(Gene symbol: LDB1)
Molecule annotation
Chemicals (4 molecules)
1
4
* Click molecule labels to explore molecular sequence information.

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