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(+) kcat is 48.1 sec(-1) for glyoxylate (at pH 8 and 37 degrees Celsius). Carbohydrate metabolism; glyoxylate cycle; (S)-malate from isocitrate: step 2/2. Monomer. By glycolate. Part of the glcDEFGB operon, which is induced by growth on glycolate, under the positive control of GlcC. Also induced by growth on acetate. Expression of the glc operon is strongly dependent on the integration host factor (IHF) and is repressed by the global respiratory regulator ArcA-P (PubMed:9880556). Cells lacking this gene are unable to oxidize glyoxylate. Belongs to the malate synthase family. GlcB subfamily.