passages.id: split_1_test_2925_passage
passages.type: progene_text
passages.text: Ionic interactions between the variable V3 domain of the HIV-1 coat glycoprotein gp120 and the amino terminal of the chemokine receptor CCR5 play a prominent role in this process , and we speculate that nature has evolved simple electrostatic interaction mechanisms which , coupled to specific recognition systems on the cell surface , can initiate and modulate certain cellular events without the need for specific molecular structures .