aa motif / Coiled-coils

Two helices are wound around each other

Alpha-helices are packed together through the hydrophobic interactions

These two helices are found to be stable in solution

They are generally found in transcription factors and intermediate filaments

They have heptad (7 amino acid) repeated sequences


TLS Online TPP Program

#Id: 3363

#Unit 3. Fundamental Processes

The two chromophores in E. coli photolyase (Mr 54,000), N5 N10-methenyltetrahydrofolylpolyglutamate (MTHF polyGlu) and FADH , perform complementary functions.

TLS Online TPP Program

#Id: 3365

#Unit 3. Fundamental Processes

In reversal, MTHF polyGlu functions as a photoantenna to absorb blue-light photons.

TLS Online TPP Program

#Id: 3368

#Unit 3. Fundamental Processes

In E. coli, DNA Pol IV (DinB) or DNA Pol V (a complex of the proteins UmuC and UmuD0 ) performs translesion synthesis. 

TLS Online TPP Program

#Id: 3369

#Unit 3. Fundamental Processes

DinB and UmuC are members of a distinct family of DNA polymerases found in many organisms known as the Y family of DNA polymerases. There are five translesion polymerases known in humans, four of which belong to the Y family.

TLS Online TPP Program

#Id: 3370

#Unit 3. Fundamental Processes

A human member of the Y family of translesion polymerases (DNA Pol h) correctly inserts two A residues opposite a thymine dimer. 

TLS Online TPP Program

#Id: 3371

#Unit 3. Fundamental Processes

Structural studies show that the active site of DNA Pol h is better at accommodating a thymine dimer than is the active site of another translesion DNA polymerase (DNA Pol k