S. Fig, DNA-binding activity analysis of Anabaena RecN. ssDNA-binding activity Analysis of RecN. The reactions contained 0.3 ?M 5-FAM labeled ssDNA 1 (Lanes 1?8)

S. Fig and P. Dnaa-gfp-foci-in-anabaena, Subcellular localization of DnaA-GFP in filaments of Anabaena (strain DG-HM) (Figure A) Subcellular localization of DnaA-GFP in dividing cell pairs (Figure B-D) The localization of DnaA-GFP foci in Anabaena. The coordinate 0 is the center of the cell. The statistical method used here was the same with that in Fig 1B (Figure E) Coordinate origin is the center of the cell. Photographs were taken by ZEISS LSM 510 META confocal laser scanning microscope, Scale bars correspond to 2 ?m. (TIF) S1 File. Sequences for EMSA Analysis. (DOC)

S. Table, Strains and plasmids used in this study. (DOC) S2 Table. Primers used in this study, DOC) References

E. Skaar, M. Lazio, and H. Seifert, Roles of the recJ and recN Genes in Homologous Recombination and DNA Repair Pathways of Neisseria gonorrhoeae, Journal of Bacteriology, vol.184, issue.4, pp.919-927, 2002.
DOI : 10.1128/jb.184.4.919-927.2002

G. Wang and R. Maier, Critical Role of RecN in Recombinational DNA Repair and Survival of Helicobacter pylori, Infection and Immunity, vol.76, issue.1, pp.153-160, 2008.
DOI : 10.1128/IAI.00791-07

I. Vlasic, R. Mertens, E. Seco, B. Carrasco, and S. Ayora, Bacillus subtilis RecA and its accessory factors, RecF, RecO, RecR and RecX, are required for spore resistance to DNA double-strand break, Nucleic Acids Res, vol.42, pp.2295-2307, 2014.

E. Michel-marks, C. Courcelle, S. Korolev, and J. Courcelle, ATP Binding, ATP Hydrolysis, and Protein Dimerization Are Required for RecF to Catalyze an Early Step in the Processing and Recovery of Replication Forks Disrupted by DNA Damage, Journal of Molecular Biology, vol.401, issue.4, pp.579-589, 2010.
DOI : 10.1016/j.jmb.2010.06.013

L. Simmons, A. Goranov, H. Kobayashi, B. Davies, and D. Yuan, Comparison of Responses to Double-Strand Breaks between Escherichia coli and Bacillus subtilis Reveals Different Requirements for SOS Induction, Journal of Bacteriology, vol.191, issue.4, pp.1152-1161, 2009.
DOI : 10.1128/JB.01292-08

O. Espeli, R. Mercier, and F. Boccard, chromosome, Molecular Microbiology, vol.23, issue.6, pp.1418-1427, 2008.
DOI : 10.1111/j.1365-2958.2008.06239.x
URL : https://hal.archives-ouvertes.fr/hal-00130779

J. Alonso, P. Cardenas, H. Sanchez, J. Hejna, and Y. Suzuki, Early steps of double-strand break repair in Bacillus subtilis, DNA Repair, vol.12, issue.3, pp.162-176, 2013.
DOI : 10.1016/j.dnarep.2012.12.005

M. Bejerano-sagie, Y. Oppenheimer-shaanan, I. Berlatzky, A. Rouvinski, and M. Meyerovich, A Checkpoint Protein That Scans the Chromosome for Damage at the Start of Sporulation in Bacillus subtilis, Cell, vol.125, issue.4, pp.679-690, 2006.
DOI : 10.1016/j.cell.2006.03.039

P. Cardenas, C. Gandara, and J. Alonso, DNA double strand break end-processing and RecA induce RecN expression levels in Bacillus subtilis, DNA Repair, vol.14, pp.1-8, 2014.
DOI : 10.1016/j.dnarep.2013.12.001

H. Sanchez, D. Kidane, C. Cozar, M. Graumann, P. Alonso et al., Recruitment of Bacillus subtilis RecN to DNA Double-Strand Breaks in the Absence of DNA End Processing, Journal of Bacteriology, vol.188, issue.2, pp.353-360, 2006.
DOI : 10.1128/JB.188.2.353-360.2006

P. Graumann and T. Knust, Dynamics of the bacterial SMC complex and SMC-like proteins involved in DNA repair, Chromosome Research, vol.18, issue.2, pp.265-275, 2009.
DOI : 10.1007/s10577-008-9014-x

D. Kidane, H. Sanchez, J. Alonso, and P. Graumann, Visualization of DNA double-strand break repair in live bacteria reveals dynamic recruitment of Bacillus subtilis RecF, RecO and RecN proteins to distinct sites on the nucleoids, Molecular Microbiology, vol.4, issue.6, pp.1627-1639, 2004.
DOI : 10.1111/j.1365-2958.2004.04102.x

E. Reyes, P. Patidar, L. Uranga, A. Bortoletto, and S. Lusetti, RecN Is a Cohesin-like Protein That Stimulates Intermolecular DNA Interactions in Vitro, Journal of Biological Chemistry, vol.285, issue.22, pp.16521-16529, 2010.
DOI : 10.1074/jbc.M110.119164

S. Pellegrino, J. Radzimanowski, D. De-sanctis, B. Erba, E. Mcsweeney et al., Structural and Functional Characterization of an SMC-like Protein RecN: New Insights into Double-Strand Break Repair, Structure, vol.20, issue.12, pp.2076-2089, 2012.
DOI : 10.1016/j.str.2012.09.010

S. Picksley, P. Attfield, and R. Lloyd, Repair of DNA double-strand breaks in Escherichia coli K12 requires a functional recN product, MGG Molecular & General Genetics, vol.40, issue.1-2, pp.267-274, 1984.
DOI : 10.1007/BF00332758

N. Sargentini and K. Smith, Quantitation of the Involvement of the recA, recB, recC, recF, recJ, recN, lexA, radA, radB, uvrD, and umuC Genes in the Repair of X-Ray-Induced DNA Double-Strand Breaks in Escherichia coli, Radiation Research, vol.107, issue.1, pp.58-72, 1986.
DOI : 10.2307/3576850

T. Meddows, A. Savory, J. Grove, T. Moore, and R. Lloyd, RecN protein and transcription factor DksA combine to promote faithful recombinational repair of DNA double-strand breaks, Molecular Microbiology, vol.11, issue.1, pp.97-110, 2005.
DOI : 10.1111/j.1365-2958.2005.04677.x

K. Keyamura, C. Sakaguchi, Y. Kubota, H. Niki, and T. Hishida, RecA Protein Recruits Structural Maintenance of Chromosomes (SMC)-like RecN Protein to DNA Double-strand Breaks, Journal of Biological Chemistry, vol.288, issue.41, pp.29229-29237, 2013.
DOI : 10.1074/jbc.M113.485474

H. Sanchez and J. Alonso, Bacillus subtilis RecN binds and protects 3'-single-stranded DNA extensions in the presence of ATP, Nucleic Acids Research, vol.33, issue.7, pp.2343-2350, 2005.
DOI : 10.1093/nar/gki533

P. Cardenas, B. Carrasco, H. Sanchez, G. Deikus, and D. Bechhofer, Bacillus subtilis polynucleotide phosphorylase 3'-to-5' DNase activity is involved in DNA repair, Nucleic Acids Research, vol.37, issue.12, pp.4157-4169, 2009.
DOI : 10.1093/nar/gkp314

K. Lemon and A. Grossman, Localization of Bacterial DNA Polymerase: Evidence for a Factory Model of Replication, Science, vol.282, issue.5393, pp.1516-1519, 1998.
DOI : 10.1126/science.282.5393.1516

J. Mascarenhas, H. Sanchez, S. Tadesse, D. Kidane, and M. Krisnamurthy, Bacillus subtilis SbcC protein plays an important role in DNA inter-strand cross-link repair, BMC Molecular Biology, vol.7, issue.1, pp.20-16780573, 2006.
DOI : 10.1186/1471-2199-7-20

D. Kidane and P. Graumann, Dynamic formation of RecA filaments at DNA double strand break repair centers in live cells, The Journal of Cell Biology, vol.6, issue.3, pp.357-366, 2005.
DOI : 10.1016/j.cub.2004.07.049

C. Zhang, S. Laurent, S. Sakr, L. Peng, and S. Bedu, Heterocyst differentiation and pattern formation in cyanobacteria: a chorus of signals, Molecular Microbiology, vol.95, issue.2, pp.367-375, 2006.
DOI : 10.1111/j.1365-2958.2005.04979.x

J. Zhang, W. Chen, and C. Zhang, hetR and patS, two genes necessary for heterocyst pattern formation, are widespread in filamentous nonheterocyst-forming cyanobacteria, Microbiology, vol.155, issue.5, pp.1418-1426, 2009.
DOI : 10.1099/mic.0.027540-0

M. Herdman, M. , R. Rosmarie, S. Roger, and Y. , Genome Size of Cyanobacteria, Journal of General Microbiology, vol.111, issue.1, pp.73-85, 1979.
DOI : 10.1099/00221287-111-1-73

D. Adams and N. Carr, Heterocyst differentiation and cell division in the cyanobacterium Anabaena cylindrica: effect of high light intensity, J Cell Sci, vol.49, pp.341-352, 1981.

S. Sakr, R. Jeanjean, C. Zhang, and T. Arcondeguy, Inhibition of Cell Division Suppresses Heterocyst Development in Anabaena sp. Strain PCC 7120, Journal of Bacteriology, vol.188, issue.4, pp.1396-1404, 2006.
DOI : 10.1128/JB.188.4.1396-1404.2006
URL : https://hal.archives-ouvertes.fr/hal-00067868

S. Sakr, M. Thyssen, M. Denis, and C. Zhang, Relationship among Several Key Cell Cycle Events in the Developmental Cyanobacterium Anabaena sp. Strain PCC 7120, Journal of Bacteriology, vol.188, issue.16, pp.5958-5965, 2006.
DOI : 10.1128/JB.00524-06
URL : https://hal.archives-ouvertes.fr/hal-00092841

X. Wei, S. Sakr, J. Li, L. Wang, and W. Chen, Expression of split dnaE genes and trans-splicing of DnaE intein in the developmental cyanobacterium Anabaena sp. PCC 7120, Research in Microbiology, vol.157, issue.3, pp.227-234, 2006.
DOI : 10.1016/j.resmic.2005.08.004
URL : https://hal.archives-ouvertes.fr/hal-00067854

R. Rippka, J. Deruelles, J. B. Waterbury, M. Herdman, and R. Y. Stanier, Generic Assignments, Strain Histories and Properties of Pure Cultures of Cyanobacteria, Microbiology, vol.111, issue.1, p.61, 1979.
DOI : 10.1099/00221287-111-1-1

C. Zhang, A gene encoding a protein related to eukaryotic protein kinases from the filamentous heterocystous cyanobacterium Anabaena PCC 7120., Proceedings of the National Academy of Sciences, vol.90, issue.24, pp.11840-11844, 1993.
DOI : 10.1073/pnas.90.24.11840

S. Zhang, G. Lin, W. Chen, L. Wang, and C. Zhang, ppGpp Metabolism Is Involved in Heterocyst Development in the Cyanobacterium Anabaena sp. Strain PCC 7120, Journal of Bacteriology, vol.195, issue.19, pp.4536-4544, 2013.
DOI : 10.1128/JB.00724-13

J. Elhai and C. Wolk, [83] Conjugal transfer of DNA to cyanobacteria, Methods Enzymol, vol.167, pp.747-754, 1988.
DOI : 10.1016/0076-6879(88)67086-8

J. Golden, S. Robinson, and R. Haselkorn, Rearrangement of nitrogen fixation genes during heterocyst differentiation in the cyanobacterium Anabaena, Nature, vol.8, issue.6010, pp.419-423, 1985.
DOI : 10.1038/314419a0

I. Kuhn, L. Peng, S. Bedu, and C. Zhang, Developmental Regulation of the Cell Division Protein FtsZ in Anabaena sp. Strain PCC 7120, a Cyanobacterium Capable of Terminal Differentiation, Journal of Bacteriology, vol.182, issue.16, pp.4640-4643, 2000.
DOI : 10.1128/JB.182.16.4640-4643.2000

Y. Yang, X. Huang, L. Wang, V. Risoul, and C. Zhang, Phenotypic variation caused by variation in the relative copy number of pDU1-based plasmids expressing the GAF domain of Pkn41 or Pkn42 in Anabaena sp. PCC 7120, Research in Microbiology, vol.164, issue.2, pp.127-135, 2013.
DOI : 10.1016/j.resmic.2012.10.010

H. Sanchez, P. Cardenas, S. Yoshimura, K. Takeyasu, and J. Alonso, Dynamic structures of Bacillus subtilis RecN-DNA complexes, Nucleic Acids Research, vol.36, issue.1, pp.110-120, 2008.
DOI : 10.1093/nar/gkm759

P. Borthakur, C. Orozco, S. Young-robbins, R. Haselkorn, and S. Callahan, Inactivation of patS and hetN causes lethal levels of heterocyst differentiation in the filamentous cyanobacterium Anabaena sp. PCC 7120, Molecular Microbiology, vol.183, issue.1, pp.111-123, 2005.
DOI : 10.1111/j.1365-2958.2005.04678.x

W. Buikema and R. Haselkorn, Characterization of a gene controlling heterocyst differentiation in the cyanobacterium Anabaena 7120., Genes & Development, vol.5, issue.2, pp.321-330, 1991.
DOI : 10.1101/gad.5.2.321

J. Frias, E. Flores, and A. Herrero, Requirement of the regulatory protein NtcA for the expression of nitrogen assimilation and heterocyst development genes in the cyanobacterium Anabaena sp. PCC7120, Molecular Microbiology, vol.175, issue.4, pp.823-832, 1994.
DOI : 10.1038/306337a0

M. Zhu, S. Callahan, and J. Allen, Maintenance of heterocyst patterning in a filamentous cyanobacterium, Journal of Biological Dynamics, vol.13, issue.6, pp.621-633, 2010.
DOI : 10.1128/JB.183.8.2605-2613.2001

D. Risser and S. Callahan, Mutagenesis of hetR Reveals Amino Acids Necessary for HetR Function in the Heterocystous Cyanobacterium Anabaena sp. Strain PCC 7120, Journal of Bacteriology, vol.189, issue.6, pp.2460-2467, 2007.
DOI : 10.1128/JB.01241-06

K. Kumar, R. Mella-herrera, and J. Golden, Cyanobacterial Heterocysts, Cold Spring Harbor Perspectives in Biology, vol.2, issue.4, p.20452939, 2010.
DOI : 10.1101/cshperspect.a000315

D. Nurnberg, V. Mariscal, J. Bornikoel, M. Nieves-morion, and N. Krauss, Intercellular Diffusion of a Fluorescent Sucrose Analog via the Septal Junctions in a Filamentous Cyanobacterium, mBio, vol.6, issue.2, p.25784700, 2015.
DOI : 10.1128/mBio.02109-14