Two-component Regulator systems

Question 1

what are Two-component Regulator systems?

Answer 1

a stimulus-response system.

Question 2

what do the Two-component Regulator systems do?

Answer 2

– detect environmental signal
– transduce signal to effector protein
– Mediate adaptive response to environmental changes
– e.g. osmotic stress, chemotaxis, oxidative stress etc.

Question 3

what does HPK stand for

Answer 3

Histadine protein kinase

Question 4

why is Cross talk in TCR rare?

Answer 4

– HPK de-phosphorylation of Response Regulator is specific
– HPK show kinetic specificity in vitro
– Surrounding AA show conservation in sub-family members

Question 5

how do Histidine Protein Kinases work?

Answer 5

• dimers as sensor domains is system specific and variable
• transmitter has 2 conserved sub-domains
  – H box–phosphorylated His forms part of the dimerisation domain
  – N-G-D/F-G box has ATP-binding activity
  and contains kinase activity