Dihydrozeatin (DZ) and isopentenyl adenine (iP) also are commonly found in higher plants and bacteria.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

Sequences that are involved with termination are called ter sites. A ter site contains a short, -23-bp sequence.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The ter site is recognized by a unidirectional contrahelicase (called Tus in E. coli and RTP in B. subtilis) that recognizes the consensus sequence and prevents the replication fork from proceeding.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The E. coli enzyme acts by antagonizing the replication helicase in a direction a) manner by direct contact between the DnaB helicase and Tus.

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#Unit 3. Fundamental Processes

Deletion of the ter sites does not, however, prevent normal replication cycles from occurring, although it does affect segregation of the daughter chromosomes.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The two replication forks meet and halt in a region approximately halfway around the chromosome from the origin.

TLS Online TPP Program

#Id: 3174

#Unit 3. Fundamental Processes

 In E. coli, two clusters of five ter sites each, including terk, -I, -E, -D, and -A on one side and terC, -B, -F, -G, and -H on the other, are located -100 kb on either side of this termination region.