STRUCTURAL COMPLEXITY OF THE SYMBIOTIC PLASMID OF RHIZOBIUM-LEGUMINOSARUM BV PHASEOLI

被引：45

作者：

GIRARD, MD ^{[1
]}

FLORES, M ^{[1
]}

BROM, S ^{[1
]}

ROMERO, D ^{[1
]}

PALACIOS, R ^{[1
]}

DAVILA, G ^{[1
]}

机构：

[1] UNIV NACL AUTONOMA MEXICO, CTR INVEST FIJAC NITROGENO, DEPT GENET MOLEC, APARTADO POSTAL 565-A, CUERNAVACA, MORELOS, MEXICO

来源：

JOURNAL OF BACTERIOLOGY | 1991年 / 173卷 / 08期

关键词：

D O I：

10.1128/jb.173.8.2411-2419.1991

中图分类号：

Q93 [微生物学];

学科分类号：

071005 ; 100705 ;

摘要：

The complete physical map of the symbiotic plasmid of Rhizobium leguminosarum bv. phaseoli strain CFN42 was established. The data support the concept that Rhizobium symbiotic genes are part of a complex genomic structure which contains a large amount of reiterated DNA sequences. This plasmid is a circular structure of 390 kb with approximately 10 families of internally reiterated DNA sequences of two to three elements each. One family includes two directly oriented nitrogenase operons situated 120 kb apart. We also found several stretches of pSym that are reiterated in other replicons of the cell. Localization of symbiotic gene sequences by heterologous hybridization revealed that nodABC sequences are separated in two regions, each of which contains a nod boxlike element, and it also suggested the presence of two copies of the nifA and nodD gene sequences. We propose that the complex structure of the symbiotic plasmid allows interactions between repeated DNA sequences which, in turn, might result in frequent rearrangements.

引用

页码：2411 / 2419

页数：9

共 56 条

[1] SPONTANEOUS TANDEM GENETIC DUPLICATIONS IN SALMONELLA-TYPHIMURIUM ARISE BY UNEQUAL RECOMBINATION BETWEEN RIBOSOMAL-RNA (RRN) CISTRONS [J].