Low-affinity receptor for leukotrienes including leukotriene B4. Mediates chemotaxis of granulocytes and macrophages. The response is mediated via G-proteins that activate a phosphatidylinositol-calcium second messenger system. The rank order of affinities for the leukotrienes is LTB4 > 12-epi-LTB4 > LTB5 > LTB3. Widely expressed. Belongs to the G-protein coupled receptor 1 family. Extended N-terminus.