Choreography of the Mycobacterium Replication Machinery during the Cell Cycle

ABSTRACT It has recently been demonstrated that bacterial chromosomes are highly organized, with specific positioning of the replication initiation region. Moreover, the positioning of the replication machinery (replisome) has been shown to be variable and dependent on species-specific cell cycle fe...

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Autores principales:	Damian Trojanowski, Katarzyna Ginda, Monika Pióro, Joanna Hołówka, Partycja Skut, Dagmara Jakimowicz, Jolanta Zakrzewska-Czerwińska
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2015
Materias:	Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/53cc69a2830c416b88b3a48d0b35395d
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spelling	oai:doaj.org-article:53cc69a2830c416b88b3a48d0b35395d2021-11-15T15:41:18ZChoreography of the Mycobacterium Replication Machinery during the Cell Cycle10.1128/mBio.02125-142150-7511https://doaj.org/article/53cc69a2830c416b88b3a48d0b35395d2015-02-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.02125-14https://doaj.org/toc/2150-7511ABSTRACT It has recently been demonstrated that bacterial chromosomes are highly organized, with specific positioning of the replication initiation region. Moreover, the positioning of the replication machinery (replisome) has been shown to be variable and dependent on species-specific cell cycle features. Here, we analyzed replisome positions in Mycobacterium smegmatis, a slow-growing bacterium that exhibits characteristic asymmetric polar cell extension. Time-lapse fluorescence microscopy analyses revealed that the replisome is slightly off-center in mycobacterial cells, a feature that is likely correlated with the asymmetric growth of Mycobacterium cell poles. Estimates of the timing of chromosome replication in relation to the cell cycle, as well as cell division and chromosome segregation events, revealed that chromosomal origin-of-replication (oriC) regions segregate soon after the start of replication. Moreover, our data demonstrate that organization of the chromosome by ParB determines the replisome choreography. IMPORTANCE Despite significant progress in elucidating the basic processes of bacterial chromosome replication and segregation, understanding of chromosome dynamics during the mycobacterial cell cycle remains incomplete. Here, we provide in vivo experimental evidence that replisomes in Mycobacterium smegmatis are highly dynamic, frequently splitting into two distinct replication forks. However, unlike in Escherichia coli, the forks do not segregate toward opposite cell poles but remain in relatively close proximity. In addition, we show that replication cycles do not overlap. Finally, our data suggest that ParB participates in the positioning of newly born replisomes in M. smegmatis cells. The present results broaden our understanding of chromosome segregation in slow-growing bacteria. In view of the complexity of the mycobacterial cell cycle, especially for pathogenic representatives of the genus, understanding the mechanisms and factors that affect chromosome dynamics will facilitate the identification of novel antimicrobial factors.Damian TrojanowskiKatarzyna GindaMonika PióroJoanna HołówkaPartycja SkutDagmara JakimowiczJolanta Zakrzewska-CzerwińskaAmerican Society for MicrobiologyarticleMicrobiologyQR1-502ENmBio, Vol 6, Iss 1 (2015)
institution	DOAJ
collection	DOAJ
language	EN
topic	Microbiology QR1-502
spellingShingle	Microbiology QR1-502 Damian Trojanowski Katarzyna Ginda Monika Pióro Joanna Hołówka Partycja Skut Dagmara Jakimowicz Jolanta Zakrzewska-Czerwińska Choreography of the Mycobacterium Replication Machinery during the Cell Cycle
description	ABSTRACT It has recently been demonstrated that bacterial chromosomes are highly organized, with specific positioning of the replication initiation region. Moreover, the positioning of the replication machinery (replisome) has been shown to be variable and dependent on species-specific cell cycle features. Here, we analyzed replisome positions in Mycobacterium smegmatis, a slow-growing bacterium that exhibits characteristic asymmetric polar cell extension. Time-lapse fluorescence microscopy analyses revealed that the replisome is slightly off-center in mycobacterial cells, a feature that is likely correlated with the asymmetric growth of Mycobacterium cell poles. Estimates of the timing of chromosome replication in relation to the cell cycle, as well as cell division and chromosome segregation events, revealed that chromosomal origin-of-replication (oriC) regions segregate soon after the start of replication. Moreover, our data demonstrate that organization of the chromosome by ParB determines the replisome choreography. IMPORTANCE Despite significant progress in elucidating the basic processes of bacterial chromosome replication and segregation, understanding of chromosome dynamics during the mycobacterial cell cycle remains incomplete. Here, we provide in vivo experimental evidence that replisomes in Mycobacterium smegmatis are highly dynamic, frequently splitting into two distinct replication forks. However, unlike in Escherichia coli, the forks do not segregate toward opposite cell poles but remain in relatively close proximity. In addition, we show that replication cycles do not overlap. Finally, our data suggest that ParB participates in the positioning of newly born replisomes in M. smegmatis cells. The present results broaden our understanding of chromosome segregation in slow-growing bacteria. In view of the complexity of the mycobacterial cell cycle, especially for pathogenic representatives of the genus, understanding the mechanisms and factors that affect chromosome dynamics will facilitate the identification of novel antimicrobial factors.
format	article
author	Damian Trojanowski Katarzyna Ginda Monika Pióro Joanna Hołówka Partycja Skut Dagmara Jakimowicz Jolanta Zakrzewska-Czerwińska
author_facet	Damian Trojanowski Katarzyna Ginda Monika Pióro Joanna Hołówka Partycja Skut Dagmara Jakimowicz Jolanta Zakrzewska-Czerwińska
author_sort	Damian Trojanowski
title	Choreography of the Mycobacterium Replication Machinery during the Cell Cycle
title_short	Choreography of the Mycobacterium Replication Machinery during the Cell Cycle
title_full	Choreography of the Mycobacterium Replication Machinery during the Cell Cycle
title_fullStr	Choreography of the Mycobacterium Replication Machinery during the Cell Cycle
title_full_unstemmed	Choreography of the Mycobacterium Replication Machinery during the Cell Cycle
title_sort	choreography of the mycobacterium replication machinery during the cell cycle
publisher	American Society for Microbiology
publishDate	2015
url	https://doaj.org/article/53cc69a2830c416b88b3a48d0b35395d
work_keys_str_mv	AT damiantrojanowski choreographyofthemycobacteriumreplicationmachineryduringthecellcycle AT katarzynaginda choreographyofthemycobacteriumreplicationmachineryduringthecellcycle AT monikapioro choreographyofthemycobacteriumreplicationmachineryduringthecellcycle AT joannahołowka choreographyofthemycobacteriumreplicationmachineryduringthecellcycle AT partycjaskut choreographyofthemycobacteriumreplicationmachineryduringthecellcycle AT dagmarajakimowicz choreographyofthemycobacteriumreplicationmachineryduringthecellcycle AT jolantazakrzewskaczerwinska choreographyofthemycobacteriumreplicationmachineryduringthecellcycle
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Choreography of the Mycobacterium Replication Machinery during the Cell Cycle

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