Structure and Mechanism of MukBEF Condensin Deciphered

2009-08-24 807
A research team of Department of Life Science’s Center for Biomolecular Recognition and Division of Molecular and Life Science, consisting of Professor Byung-Ha Oh, Doctor Jae-Sung Woo, and Doctor Jae-Hong Lim, has solved secrets of the ring-shaped molecular structure of the MukBEF condensin, the key mediator of chromosome condensation.

In eukaryotic organisms, chromosomes are found in the nucleus of every cell. Before cell division, chromosomes are condensed, and the two replicated copies of the chromosomes are partitioned into the two daughter cells. In prokaryotic organisms, chromosome condensation also takes place to insure partitioning of the replicated chromosomal copies into two newly divided cells.

Chromosomes are long DNA molecules, ~1,000-10,000 times longer than the size of normal cells. How such a huge molecule can fit into a small volume in a cell and how the cell can divide replicated chromosomes into two exact halves without tangling and tearing is still a baffling mystery.

Chromosome condensation is a well-known phenomenon, even mentioned in middle and high school textbooks, but the underlying mechanisms have been elusive. Professor Oh’s team brought to light the protein complex’s molecular structure as well as the functional mechanism.

The findings are also expected to be utilized in applied research for development of antibiotics or anticancer substances, since cells cannot grow normally when chromosome condensation is hindered.

The research outcomes were presented in the January 9, 2009 online issue of Cell.

“This is only the beginning of research in the chromosome condensation area,” evaluated Professor Oh, declaring the team’s plans to continue research in condensation mechanism in eukaryotic cells which have more than one chromosome. He added that compared to prokaryotic cells, “condensation in eukaryotic cells is estimated to be controlled by much more intricate mechanisms because each chromosome is condensed separately.”