For most, but not all, RTKs, the weakly active kinase in each subunit is phosphorylate a key tyrosine in the activation loop of the other subunit (trans-phosphorylation)

TLS Online TPP Program

#Id: 401

#Unit 2. Cellular Organization

Canonical H3 also known as H3.1 differs from the H3.3 variant at only four amino acid positions—three in the histone core and one in the N-terminal tail.

TLS Online TPP Program

#Id: 402

#Unit 2. Cellular Organization

Centromeric H3 (or CenH3) histone, known as Cse4 in yeast. CenH3 histones are incorporated into specialized nucleosomes present at centromeres.

TLS Online TPP Program

#Id: 403

#Unit 2. Cellular Organization

CenH3 has a unique N terminus, which does not resemble other core histones.

TLS Online TPP Program

#Id: 404

#Unit 2. Cellular Organization

Most H2A variants contain alternative C-termini, except H2ABbd, which contains a distinct N terminus.

TLS Online TPP Program

#Id: 405

#Unit 2. Cellular Organization

SpH2B has a long N-terminus and functions in Chromatin packaging

TLS Online TPP Program

#Id: 406

#Unit 2. Cellular Organization

In yeast, centromeric nucleosomes consist of Cse4, H4, and a nonhistone protein Scm3, in place of H2A-H2B dimers.