Involved in the glycolate utilization. Catalyzes the condensation and subsequent hydrolysis of acetyl-coenzyme A (acetyl-CoA) and glyoxylate to form malate and CoA. acetyl-CoA + glyoxylate + H2O = (S)-malate + CoA + H(+) Mg(2+). Co(2+) or Mn(2+) could partially replace magnesium. Inhibited by oxalate, glycolate and ATP. Optimum pH is 7.6. Optimum temperature is 43 degrees Celsius. Carbohydrate metabolism; glyoxylate cycle; (S)-malate from isocitrate: step 2/2. Monomer. Activated by RamA and repressed by RamB. Cells lacking this gene show the absence of malate synthase activity and to the inability to grow on acetate. Belongs to the malate synthase family. GlcB subfamily.