The Klenow fragment is a large protein fragment produced when DNA polymerase I from E. coli is enzymatically cleaved by the protease subtilisin.

DNA Polymerase I, Large (Klenow) Fragment is a proteolytic product of E. coli DNA Polymerase I which retains polymerization and 3'→ 5' exonuclease activity, but has lost 5'→ 3' exonuclease activity (1). Klenow retains the polymerization fidelity …

Klenow Fragment (3´→ 5´ exo-) is an N-terminal truncation of DNA Polymerase I which retains polymerase activity, but has lost the 5´→ 3´ exonuclease activity and has mutations (D355A, E357A) which abolish the 3´→ 5´ exonuclease activity (1).

Definition: It is the large fragment of DNA polymerase I enzyme of E.coli produced by the proteolytic cleavage of DNA pol I by protease subtilisin. Refer this figure for clear understanding. On the right side is the DNA Polymerase I before treating with protease.

Klenow Fragment is a mesophilic DNA polymerase derived from the E. coli Polymerase I DNA-dependent repair enzyme. The enzyme exhibits DNA synthesis and proofreading (3ʹ→5ʹ) nuclease activities and, in the absence of the holoenzyme’s (5ʹ→3ʹ) nuclease domain, displays a moderate strand displacement activity during DNA synthesis.

DNA Polymerase I Large (Klenow) Fragment consists of a single polypeptide chain (68kDa) that lacks the 5´->3´ exonuclease activity of intact E. coli DNA polymerase I, but retains its 5´->3´ polymerase, 3´->5´ exonuclease and strand displacement activities.

A Klenow fragment is a protein fragment derived from DNA polymerase I through proteolysis, often used in recombinant DNA technology for its DNA polymerase activity. AI generated definition based on: Enzymology Primer for Recombinant DNA Technology, 1996

Klenow Fragment is the Large Fragment of DNA Polymerase I, E.coli. It exhibits 5'→3' polymerase activity and 3'→5' exonuclease (proofreading) activity, but lacks 5'→3' exonuclease activity of DNA Polymerase I. DNA blunting by fill-in of 5’-overhangs or removal of 3‘-overhangs. (1), see protocols on back page. Random-primed DNA labeling (2-4).

May 1, 2020 · Pol I can be cleaved by mild treatment with subtilisin into two fragments; the larger fragment is known as the Klenow fragment. The Klenow fragment retains the polymerizing activity and the 3' → 5' exonuclease of the holo-enzyme but …

Following its discovery by Klenow and Henningsen (1970), the large fragment has been called the “Klenow fragment.” In order to polymerize the addition of nucleotides to the 3′‐OH end of DNA, the Klenow fragment requires a single‐stranded DNA template and a DNA or RNA primer with a 3′‐OH terminus.