1TUB

TUBULIN ALPHA-BETA DIMER, ELECTRON DIFFRACTION

Summary for 1TUB

• Entry DOI: 10.2210/pdb1tub/pdb
• Descriptor: TUBULIN, GUANOSINE-5'-TRIPHOSPHATE, GUANOSINE-5'-DIPHOSPHATE, ... (5 entities in total)
• Functional Keywords: microtubules, alpha-tubulin, beta-tubulin, gtpase
• Biological source: Sus scrofa (pig); More
• Cellular location: Cytoplasm, cytoskeleton: P02550 P02554
• Total number of polymer chains: 2
• Total formula weight: 98584.32

Authors

Nogales, E.,Downing, K.H. (deposition date: 1997-09-23, release date: 1998-10-07, Last modification date: 2024-12-25)

Primary citation

Nogales, E.,Wolf, S.G.,Downing, K.H.
Structure of the alpha beta tubulin dimer by electron crystallography.
Nature, 391:199-203, 1998

PubMed Abstract: The alphabeta tubulin heterodimer is the structural subunit of microtubules, which are cytoskeletal elements that are essential for intracellular transport and cell division in all eukaryotes. Each tubulin monomer binds a guanine nucleotide, which is nonexchangeable when it is bound in the alpha subunit, or N site, and exchangeable when bound in the beta subunit, or E site. The alpha- and beta-tubulins share 40% amino-acid sequence identity, both exist in several isotype forms, and both undergo a variety of posttranslational modifications. Limited sequence homology has been found with the proteins FtsZ and Misato, which are involved in cell division in bacteria and Drosophila, respectively. Here we present an atomic model of the alphabeta tubulin dimer fitted to a 3.7-A density map obtained by electron crystallography of zinc-induced tubulin sheets. The structures of alpha- and beta-tubulin are basically identical: each monomer is formed by a core of two beta-sheets surrounded by alpha-helices. The monomer structure is very compact, but can be divided into three functional domains: the amino-terminal domain containing the nucleotide-binding region, an intermediate domain containing the Taxol-binding site, and the carboxy-terminal domain, which probably constitutes the binding surface for motor proteins.

PubMed: 9428769
DOI: 10.1038/34465

Experimental method

ELECTRON CRYSTALLOGRAPHY (3.7 Å)