5O01

Crystal structure of BtubC (BKLC) from P. vanneervenii

Summary for 5O01

• Entry DOI: 10.2210/pdb5o01/pdb
• Descriptor: BKLC (bacterial kinesin-light chain-like) (2 entities in total)
• Functional Keywords: bacterial cytoskeleton, mini microtubules, motor protein
• Biological source: Prosthecobacter vanneervenii
• Total number of polymer chains: 2
• Total formula weight: 58440.30

Authors

Lowe, J.,Deng, X. (deposition date: 2017-05-15, release date: 2017-07-19, Last modification date: 2024-05-08)

Primary citation

Deng, X.,Fink, G.,Bharat, T.A.M.,He, S.,Kureisaite-Ciziene, D.,Lowe, J.
Four-stranded mini microtubules formed by Prosthecobacter BtubAB show dynamic instability.
Proc. Natl. Acad. Sci. U.S.A., 114:E5950-E5958, 2017

PubMed Abstract: Microtubules, the dynamic, yet stiff hollow tubes built from αβ-tubulin protein heterodimers, are thought to be present only in eukaryotic cells. Here, we report a 3.6-Å helical reconstruction electron cryomicroscopy structure of four-stranded mini microtubules formed by bacterial tubulin-like BtubAB proteins. Despite their much smaller diameter, mini microtubules share many key structural features with eukaryotic microtubules, such as an M-loop, alternating subunits, and a seam that breaks overall helical symmetry. Using in vitro total internal reflection fluorescence microscopy, we show that bacterial mini microtubules treadmill and display dynamic instability, another hallmark of eukaryotic microtubules. The third protein in the gene cluster, BtubC, previously known as "bacterial kinesin light chain," binds along protofilaments every 8 nm, inhibits BtubAB mini microtubule catastrophe, and increases rescue. Our work reveals that some bacteria contain regulated and dynamic cytomotive microtubule systems that were once thought to be only useful in much larger and sophisticated eukaryotic cells.

PubMed: 28673988
DOI: 10.1073/pnas.1705062114

Experimental method

X-RAY DIFFRACTION (2.5 Å)