Involved in the biosynthesis of the herbicide bialaphos (BA). Catalyzes the condensation berween phosphinopyruvic acid (PPA), an analog of oxalacetic acid, and acetyl-CoA to form R-2-phosphinomethylmalic acid (PMM) (PubMed:3781934, PubMed:3170341). Can also act on oxaloacetate, but shows no activity when acetyl-CoA is substituted by propionyl-CoA or butyryl-CoA (PubMed:3170341). 3-(hydrohydroxyphosphoryl)pyruvate + acetyl-CoA + H2O = CoA + H(+) + phosphinomethylmalate Can also use magnesium, calcium and iron ions with lower efficiency. Strongly inhibited by p-chloromercuribenzoate (pCMB), iodoacetamide (IA) and EDTA. Optimum pH is 8. Optimum temperature is 30 degrees Celsius. Homodimer. Belongs to the alpha-IPM synthase/homocitrate synthase family.