DNA Segregation in Natural and Synthetic Minimal Systems

Abstract

Faithful segregation of replicated genomes to dividing daughter cells is a major hallmark of cellular life and needs to be part of the future design of the robustly proliferating minimal cell. So far, the complexity of eukaryotic chromosome segregation machineries has limited their applicability to synthetic systems. Prokaryotic plasmid segregation machineries offer promising alternative tools for bottom‐up synthetic biology, with the first three‐component DNA segregation system being reconstituted a decade ago. In this review, the mechanisms underlying DNA segregation in prokaryotes, with a particular focus on segregation of plasmids and chromosomal replication origins are reviewed, along with a brief discussion of archaeal and eukaryotic systems. In addition, this review shows how in vitro reconstitution has allowed deeper insights into these processes and discusses possible applications of these machineries for a minimal synthetic segrosome as well as the challenge of its coupling to a minimal replisome.

Functional Modules of Minimal Cell Division for Synthetic Biology

“…[1,2,5] The knowledge ii) Segregation of the bulk of the chromosome iii) Separation of the ter regions While E. coli is the most studied model organism, the details of how it (and other bacteria) manage chromosome segregation remain incomplete. [26] In the case of E. coli and other gammaproteobacteria that lack ParABS systems, the mechanisms underlying origin segregation and positioning are unknown. The segregation of the ori regions, which dictates the directionality and influences the final chromosome configuration, is poorly understood in E. coli.…”

“…They are closely related to plasmid-based ParABS systems, which are discussed in detail elsewhere in this issue. [26] In the case of E. coli and other gammaproteobacteria that lack ParABS systems, the mechanisms underlying origin segregation and positioning are unknown. However, other proteins that actively establish gradients, such as MukBEF, [27,28] have been hypothesized to play a similar role.…”

Cytoskeletal and Actin‐Based Polymerization Motors and Their Role in Minimal Cell Design

“…ParM interacts with the ParR-parC complex to assembly into a mitotic-like spindle to push plasmids to opposite poles of the cell. [23] [13] In comparison, domain IB is missing a helix that is present in MreB and actin and also shows an unusual insertion of a strand from domain IA that is not observed for any other member of the actin family.…”

“…Further details about proteins involved in DNA segregation have been discussed elsewhere in this issue. [23]…”

Lessons from a Minimal Genome: What Are the Essential Organizing Principles of a Cell Built from Scratch?

“…The partition site is functionally analogous to ae ukaryotic centromere and iss pecificallyb ound by one of the proteins to form ap artition complex. Other modes of segregation are emerging (reviewedi nH ürtgen et al [37] ). Par systems have been categorized accordingt ow hether the NTPase contains aW alker ATP-binding motif (ParA), or resembles eukaryotic actin (usually called ParM) or tubulin (TubZ; reviewed in Gerdes et al [36] ).…”