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Cell size and nucleoid organization of engineered Escherichia coli cells with a reduced genome
Author(s) -
Hashimoto Masayuki,
Ichimura Toshiharu,
Mizoguchi Hiroshi,
Tanaka Kimie,
Fujimitsu Kazuyuki,
Keyamura Kenji,
Ote Tomotake,
Yamakawa Takehiro,
Yamazaki Yukiko,
Mori Hideo,
Katayama Tsutomu,
Kato Junichi
Publication year - 2005
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2004.04386.x
Subject(s) - nucleoid , biology , escherichia coli , genome , genetics , genomic organization , escherichia coli proteins , computational biology , microbiology and biotechnology , gene
Summary The minimization of a genome is necessary to identify experimentally the minimal gene set that contains only those genes that are essential and sufficient to sustain a functioning cell. Recent developments in genetic techniques have made it possible to generate bacteria with a markedly reduced genome. We developed a simple system for formation of markerless chromosomal deletions, and constructed and characterized a series of large‐scale chromosomal deletion mutants of Escherichia coli that lack between 2.4 and 29.7% of the parental chromosome. Combining deletion mutations changes cell length and width, and the mutant cells with larger deletions were even longer and wider than the parental cells. The nucleoid organization of the mutants is also changed: the nucleoids occur as multiple small nucleoids and are localized peripherally near the envelope. Inhibition of translation causes them to condense into one or two packed nucleoids, suggesting that the coupling of transcription and translation of membrane proteins peripherally localizes chromosomes. Because these phenotypes are similar to those of spherical cells, those may be a consequence of the morphological change. Based on the nucleoid localization observed with these mutants, we discuss the cellular nucleoid dynamics.