ISfinder Mirror Site

IS21

Family IS21
Group

MGE type ISRelated element(s) :
Isoform Synonym(s) IS8

Accession number	Transposition	Origin	Host
X14793	Y	Pseudomonas aeruginosa	Pseudomonas aeruginosa PAO25 plasmid pR68.45

DNA section

IS Length : 2131 bp

Ends

IR Length : 30/42

IRL : TGTCAGCGCCAGTGATATAAGACGGTAATTCACCATTTGGATTGTCCGCT
IRR : TGTCAACGCCACGATGTTTGACCGTTATTTGCCATTTTCATGCCCGCTAA

Insertion site

Left flank	Direct repeat	Right flank	DR Length
NNNNNNNTTC	TCGG	AGCNNNNNNN	4
NNNNNNNTTC	TCGG	AGCNNNNNNN	4
NNNNNNNGCG	CCTA	TATNNNNNNN	4
NNNNNNNGCG	CCTA	TATNNNNNNN	4
NNNNNNNGTC	AGGC	ACCNNNNNNN	4
NNNNNNNCCA	CTAT	CGANNNNNNN	4
NNNNNNNTGT	TGGG	CGCNNNNNNN	4
NNNNNNNCCA	TTCC	GACNNNNNNN	4
NNNNNNNCCG	GTAC	TGCNNNNNNN	4
NNNNNNNAGT	CAGGC	ACCNNNNNNN	5

DNA sequence

TGTCAGCGCCAGTGATATAAGACGGTAATTCACCATTTGGATTGTCCGCTCCACCCAACATGTTGTTTCCTTAAGGTTCTCACACCAGAAAGGACATCAA
CATGCTGAGCAGAGAGGACTTTTACATGATAAAGCAAATGCGCCAGCAGGGCGCGTACATTGTCGATATTGCGACTCAGATTGGTTGCTCTGAACGGACG
GTCAGACGCTACCTCAAATACCCTGAACCGCCAGCCAGAAAGACCCGCCACAAAATGGTTAAGCTGAAACCGTTTATGGATTACATCGACATGCGCCTGG
CAGAGAATGTCTGGAATAGTGAGGTTATCTTTGCGGAGATTAAGGCAATGGGTTATACGGGCGGACGTTCCATGCTGCGTTACTACATCCAGCCCAAACG
TAAAATGCGTCCGTCAAAAAGAACAGTTCGCTTCGAAACTCAGCCTAGATACCAGCTCCAGCACGACTGGGGCGAAGTTGAGGTGGAGGTTGCCGGGCAA
CGGTGCAAAGTTAACTTTGCGGTTAATACGCTGGGGTTCTCCCGCCGCTTCCATGTCTTCGCCGCACCAAAACAGGATGCTGAGCATACCTACGAATCAC
TGGTTCGCGCCTTCCGCTACTTCGGTGGTTGTGTGAAAACGGTGCTGGTTGATAACCAGAAGGCTGCGGTGCTGAAGAATAACAACGGGAAAGTCGTGTT
CAACTCCGGATTCCTGTTGCTGGCCGACCACTATAACTTCCTGCCACGGGCATGCCGTCCACGCAGGGCCAGAACAAAAGGTAAGGTTGAGCGGATGGTG
AAATACCTCAAGGAGAACTTCTTCGTTCGGTACCGCAGGTTCGACAGCTTCACTCATGTTAATCAACAACTGGAGCAATGGATAGCCGATGTGGCTGACA
AACGGGAACTTCGCCAGTTCAAAGAAACGCCGGAACAGCGCTTCGCGCGTGAGCAGGAACATCTGCAGCCGTTACCGGATACGGACTTCGATACCAGTTA
CTTCGACATCCGCCATGTGTCCTGGGACAGCTATATCGAGGTTGGTGGTAATCGTTACAGCGTTCCCGAAGCGCTGTGTGGTCAGCCGGTATCGATACGA
ATATCGCTGGATGACGAGTTGCGGATCTACAGTAATGAGAAACTGGTGGCCTCACATCGCCTCTGTTCGGCATCGTCTGGCTGGCAGACAGTGCCGGAGC
ATCACGCCCCGCTCTGGCAGCAGGTCAGTCAGGTGGAACATCGACCACTGAGTGCCTATGAGGAGCTGTTGTGATGCATGAGCTGGAAGTCCTGCTGAGT
CGCCTGAAAATGGAGCATCTGAGTTATCACGTTGAAAGCCTGCTGGAACAGGCAGCTAAAAAAGAGCTGAACTACCGGGAGTTCCTGTGCATGGCGCTAC
AGCAGGAATGGAACGGCAGGCATCAGCGCGGTATGGAGTCCAGGCTGAAGCAGGCTCGTCTGCCGTGGGTCAAAACGCTGGAGCAGTTCGACTTTACCTT
CCAGCCGGGCATCGACCGTAAGGTTGTCCGGGAACTGGCTGGTCTGGCGTTCGTGGAGCGCAGCGAAAACGTGATCCTGCTGGGACCTCCTGGTGTCGGA
AAAACTCATCTGGCCATAGCTCTTGGCGTGAAAGCGGTGGATGCGGGACATCGGGTACTGTTTATGCCACTGGACAGACTGATCGCGACACTGATGAAAG
CGAAAGAGGAAAACCGGCTGGAGCGTCAGCTGCAGCAACTGAGTTATGCCCGGGTGTTGATCCTGGATGAAATAGGCTATCTGCCCATGAACAGAGAGGA
AGCCAGCCTGTTCTTCCGGCTACTGAACCGTCGATATGAAAAAGCGAGCATCATACTGACGTCAAACAAAGGGTTCGCAGACTGGGGAGAAATGTTCGGA
GATCACGTGCTGGCAACAGCGATACTGGATCGGTTGCTACATCACTCAACCACGCTGAATATCAAAGGAGAGAGTTACCGGTTAAAAGAGAAACGTAAAG
CTGGAGTGCTGACCAAAAACACAACGCCAATCAGTGATGATGAAATGGTGAAAAGCGGACAGCATCAGTAACGAAAGTATCTTAGCGGGCATGAAAATGG
CAAATAACGGTCAAACATCGTGGCGTTGACA

Protein section

ORF number : 2

ORF 1

Length		Begin	End	Strand	Fusion ORF
1173 bp	390 aa	102	1274	+	No

ORF function : Transposase
Chemistry : DDE

ORF sequence :

MLSREDFYMIKQMRQQGAYIVDIATQIGCSERTVRRYLKYPEPPARKTRHKMVKLKPFMDYIDMRLAENVWNSEVIFAEIKAMGYTGGRSMLRYYIQPKR
KMRPSKRTVRFETQPRYQLQHDWGEVEVEVAGQRCKVNFAVNTLGFSRRFHVFAAPKQDAEHTYESLVRAFRYFGGCVKTVLVDNQKAAVLKNNNGKVVF
NSGFLLLADHYNFLPRACRPRRARTKGKVERMVKYLKENFFVRYRRFDSFTHVNQQLEQWIADVADKRELRQFKETPEQRFAREQEHLQPLPDTDFDTSY
FDIRHVSWDSYIEVGGNRYSVPEALCGQPVSIRISLDDELRIYSNEKLVASHRLCSASSGWQTVPEHHAPLWQQVSQVEHRPLSAYEELL

Blast result :

ORF 2

Length		Begin	End	Strand	Fusion ORF
798 bp	265 aa	1274	2071	+	No

ORF function : Accessory Gene
AG : IS21 helper

ORF sequence :

MHELEVLLSRLKMEHLSYHVESLLEQAAKKELNYREFLCMALQQEWNGRHQRGMESRLKQARLPWVKTLEQFDFTFQPGIDRKVVRELAGLAFVERSENV
ILLGPPGVGKTHLAIALGVKAVDAGHRVLFMPLDRLIATLMKAKEENRLERQLQQLSYARVLILDEIGYLPMNREEASLFFRLLNRRYEKASIILTSNKG
FADWGEMFGDHVLATAILDRLLHHSTTLNIKGESYRLKEKRKAGVLTKNTTPISDDEMVKSGQHQ

Blast result :

Comments

IS21 was first observed in R68.45 as a direct duplication of a 2 kb fragment of the original R68 plasmid. It is involved in conduction of the bacterial chromosome and the pTi plasmid, via "cointegrate formation", but also promotes adjacent deletions. However, cointegrate formation proceeds first through an adjacent transposition of IS21 in the donor molecule, and then transposition of that structure (tandem direct repeat of IS21) in the target molecule thereby generating a typical cointegrate molecule which can be resolved in a recA+ strain. In the "intermediate" structure (IS21)2, a new promoter is created at the junction (-35 box in the right IR of the right copy and a -10 box at the left end of the left IS21 copy) and activates the transpositional activity of the left copy (Reimmann et al., 1989). IS21 has the tendency to insert within or very close to the ends of IS21 (Reimmann and Haas, 1987). All the above results suggest a conservative, "cut-and-paste" transposition mechanism for IS21. The istA gene is responsible for the 3'-end cleavages but istB is also required for cointegrate formation (Reimmann and Haas, 1990). IS21 is located upstream of the kanamycin resistance determinant of plasmid RP4 (= R18, R68, RK2, or RP1), and carries the -35 promoter box of the aphA gene. IS21 is similar to IS232 and IS640. In Escherichia coli, the first 106-bp of IS21 were found downstream of the nadE (NH3-dependent NAD synthetase) gene, at position 38.1 min (M15328).

References