Chromosomes are condensed in all forms of life. SMC-based condensins are the key mediators in this Process, but their molecular mechanisms remain elusive. Two different condensin complexes have been identified in prokaryotic organisms: MukB-MUkE-MukF and SMC-ScpA-ScpB. This review focuses on comparison between the two machineries based on structural, biochemical and other related information in the light of their Structure and function. (C) 2009 Elsevier Inc. All rights reserved.