Replication enzymes have large structures, with separate subunits for different activities. Repair enzymes have much simpler structures.

TLS Online TPP Program

#Id: 1458

#Unit 4. Cell Communication and Cell Signaling

The formation of many cell-cell adhesions entails two types of molecular interactions:

1. Trans binding interactions 

2. Cis binding interactions

TLS Online TPP Program

#Id: 1459

#Unit 4. Cell Communication and Cell Signaling

In trans interactions (intercellular or adhesive interactions) CAMs on one cell bind to the CAMs on an adjacent cell. 

TLS Online TPP Program

#Id: 1460

#Unit 4. Cell Communication and Cell Signaling

In cis interactions (intracellular or lateral interactions) monomeric CAMs on one cell bind to one or more CAMs in the same cell’s plasma membrane.

TLS Online TPP Program

#Id: 1461

#Unit 4. Cell Communication and Cell Signaling

CAMs fall into one of four major families: 

• Cadherins

• Immunoglobulin (Ig) superfamily

• Integrins

• Selectins

TLS Online TPP Program

#Id: 1462

#Unit 4. Cell Communication and Cell Signaling

The adhesiveness of cadherins depends on the presence of extracellular Ca2+.

TLS Online TPP Program

#Id: 1463

#Unit 4. Cell Communication and Cell Signaling

Two type of Cadherins:

1. Classical cadherin proteins

2. Nonclassical cadherin proteins