The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein. Binds 1 lipoyl cofactor covalently. The glycine cleavage system is composed of four components that only loosely associate: the P protein (EC 1.4.4.2), the T protein (EC 2.1.2.10), the L protein (EC 1.8.1.4) and the lipoyl-bearing H protein. This alternative splicing is restricted to C4 species of Flaveria. Expressed in roots, stems and leaves. Major isoform in stems and leaves. Major isoform in roots. Belongs to the GcvH family.