Yes. The native aortic valve closes by coaptation: during diastole, aortic pressure becomes higher than left ventricular pressure, causing the three cusps to move centrally and their free edges overlap/appose along coaptation zones. This creates a seal that prevents aortic regurgitation.

Each cusp has a coaptation region with adjacent cusps; the central nodules of Arantius help complete the central seal. If the cusps fail to meet adequately, such as with aortic-root dilatation, cusp prolapse, retraction, or perforation, this is malcoaptation and produces aortic regurgitation. The echocardiography text specifically describes a coaptation zone on each aortic leaflet with overlap between adjacent leaflets (Textbook of Clinical Echocardiography, lines 1614-1618).

So, yes: coaptation is the mechanism of competent aortic-valve closure, though unlike the mitral valve it involves three semilunar cusps and does not involve chordae tendineae.