or AluI sequence or Alu repeat or AluI repeat
any of various base sequences dispersed in human, rat, and mouse (and perhaps other) genomes of ≈0.3 kbp and spaced at approximately 5 kbp. Each Alu sequence comprises two similar 130 bp sequences (
Alu left and
Alu right) separated by a short A-rich region. Alu sequences are the major
SINE in the human genome, being present ≈10
6 times. They are responsible for Alu-mediated deletions in several genes in which they occur (e.g. that for C1 inhibitor). These sequences may be sites for attachment of cohesin complexes that bind newly replicated chromosomes before they segregate into daughter cells. The name derives from the presence in such sequences of sites for the restriction enzyme
AluI. See
hereditary angioedema.