The Sinorhizobium meliloti insertion sequence (IS) elements ISRm102F34-1/ISRm7 and ISRm220-13-5 belong to a new family of insertion sequence elements |
| |
| Authors: | Selbitschka W Zekri S Schröder G Pühler A Toro N |
| |
| Institution: | 1. Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany;2. Departamento de Microbiolog??a del Suelo y Sistemas Simbióticos, Estación Experimental del Zaid??n, Consejo Superior de Investigaciones Cient??ficas, Profesor Albareda 1, 18008 Granada, Spain;1. Botany Department, Faculty of Science, Menoufiya University, Shebin El-Kom, Menoufiya Governorate, Egypt;2. Environmental Studies and Research Institute (ESRI), University of Sadat City, P.O. 32897 Sadat City, Menoufiya Governorate, Egypt;3. Department of Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, CSIC, P.O. Box 419, 18080 Granada, Spain;1. Department of Animal Biology and Genetics, University of Florence, via Romana 17, I-50125 Firenze, Italy;2. Research Institute for Agricultural Microbiology (RIAM), Sh. Podbelsky 3, St.-Petersburg-Pushkin 8, 196608, Russia;3. N.I. Vavilov Institute For Plant Genetics Resources, B. Morskaya 42, St.-Petersburg 190000, Russia;1. Laboratoire des Interactions Légumineuses-Microorganismes, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-Lif, Tunisia;2. Laboratoire des Symbioses Tropicales et Méditerranéennes, CIRAD/INRA/IRD/SupAgro/UM2, UMR113, 34398 Montpellier Cedex, France;1. Center for Biotechnology, Institute for Genome Research and Systems Biology, Bielefeld University, D-33615 Bielefeld, Germany;2. Department of Biological Sciences, Life Sciences I, Virginia Tech, Blacksburg, VA 24061, USA |
| |
| Abstract: | The Sinorhizobium meliloti insertion sequence (IS) elements ISRm102F34-1 and ISRm220-13-5 are 1481 and 1550 base pairs (bp) in size, respectively. ISRm102F34-1 is bordered by 15 bp imperfect terminal inverted repeat sequences (two mismatches), whereas the terminal inverted repeat of ISRm220-13-5 has a length of 16 bp (two mismatches). Both insertion sequence elements generate a 6-bp target duplication upon transposition. The putative transposase enzymes of ISRm102F34-1 and ISRm220-13-5 consist of 449 or 448 amino acid residues with predicted molecular weights of 50.7 or 51.3 kDa and theoretical isoelectric points of 10.8 or 11.1, respectively. ISRm102F34-1 is identical in 98.9% of its nucleotide sequence to an apparently inactive copy of an insertion sequence element, designated ISRm7, which flanks the left-end of the nodule formation efficiency (nfe) region of plasmid pRmeGR4b of S. meliloti strain GR4. ISRm102F34-1 and ISRm220-13-5 are closely related since they show an overall identity of 57.0% at the nucleotide sequence level and of 47.3% at the deduced amino acid level of their putative transposases. Both insertion sequence elements displayed significant similarity to the Xanthomonas campestris ISXc6 and its homolog IS1478a. Since none of these insertion sequence elements could be allocated to existing families of insertion sequence elements, a new family is proposed. Analysis of the distribution of ISRm102F34-1/ISRm7 in various local S. meliloti populations sampled from Medicago sativa, Medicago sphaerocarpa and Melilotus alba host plants at different locations in Spain revealed its presence in 35% of the isolates with a copy number ranging from 1 to 5. Furthermore, ISRm102F34-1/ISRm7 homologs were identified in other rhizobial species. |
| |
| Keywords: | Transposable elements Transposase Copy number Rhizobium meliloti pRmeGR4b Non-pSym plasmid |
| 本文献已被 ScienceDirect PubMed 等数据库收录！ |
|
