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repressor

American  
[ri-pres-er] / rɪˈprɛs ər /

noun

  1. represser.

  2. Genetics. a protein that binds DNA at an operator site and thereby prevents transcription of one or more adjacent genes.


repressor British  
/ rɪˈprɛsə /

noun

  1. biochem a protein synthesized under the control of a repressor gene, which has the capacity to bind to the operator gene and thereby shut off the expression of the structural genes of an operon

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

repressor Scientific  
/ rĭ-prĕsər /
  1. A protein that binds to an operator, blocking transcription of an operon and the enzymes for which the operon codes.


Etymology

Origin of repressor

From Latin, dating back to 1955–60; repress, -tor

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

What would be the result of a mutation in the repressor protein that prevented it from binding lactose?

From Textbooks • Jun. 9, 2022

If lactose is present, the repressor protein does not bind to its operator.

From Textbooks • Jun. 9, 2022

The repressor will bind the operator in the presence of lactose.

From Textbooks • Jun. 9, 2022

When lactose is present, an end product of lactose metabolism binds to the repressor protein and prevents it from binding to the operator.

From Textbooks • Apr. 25, 2013

Another repressor, from a virus, was isolated by Mark Ptashne and Nancy Hopkins in 1966.

From "The Gene" by Siddhartha Mukherjee