1KHI

CRYSTAL STRUCTURE OF HEX1

Summary for 1KHI

• Entry DOI: 10.2210/pdb1khi/pdb
• Descriptor: Hex1 (2 entities in total)
• Functional Keywords: hex1, neurospora crassa, membrane sealing, peroxisomal target, structural protein
• Biological source: Neurospora crassa
• Cellular location: Peroxisome: P87252
• Total number of polymer chains: 1
• Total formula weight: 19150.66

Authors

Yuan, P.,Swaminathan, K. (deposition date: 2001-11-30, release date: 2002-11-30, Last modification date: 2024-05-29)

Primary citation

Yuan, P.,Jedd, G.,Kumaran, D.,Swaminathan, S.,Shio, H.,Hewitt, D.,Chua, N.-H.,Swaminathan, K.
A HEX-1 crystal lattice required for Woronin body function in Neurospora crassa
NAT.STRUCT.BIOL., 10:264-270, 2003

PubMed Abstract: The Woronin body is a dense-core vesicle specific to filamentous ascomycetes (Euascomycetes), where it functions to seal the septal pore in response to cellular damage. The HEX-1 protein self-assembles to form this solid core of the vesicle. Here, we solve the crystal structure of HEX-1 at 1.8 A, which provides the structural basis of its self-assembly. The structure reveals the existence of three intermolecular interfaces that promote the formation of a three-dimensional protein lattice. Consistent with these data, self-assembly is disrupted by mutations in intermolecular contact residues and expression of an assembly-defective HEX-1 mutant results in the production of aberrant Woronin bodies, which possess a soluble noncrystalline core. This mutant also fails to complement a hex-1 deletion in Neurospora crassa, demonstrating that the HEX-1 protein lattice is required for Woronin body function. Although both the sequence and the tertiary structure of HEX-1 are similar to those of eukaryotic initiation factor 5A (eIF-5A), the amino acids required for HEX-1 self-assembly and peroxisomal targeting are absent in eIF-5A. Thus, we propose that a new function has evolved following duplication of an ancestral eIF-5A gene and that this may define an important step in fungal evolution.

PubMed: 12640443
DOI: 10.1038/nsb910

Experimental method

X-RAY DIFFRACTION (1.78 Å)