CONFLICT OF INTERESTS
The authors declare that there are no conflict of interests.
ABBREVIATIONS BCKDH, branched-chain alpha-ketoacid dehydrogenase complex; C1, one-carbon; GCS, glycine cleavage system; Hapo, apo-H protein; HK64A, a mutant protein of Hapo with mutation of the key residue lysine64 into alanine; Hlip, lipoylated form of H protein; KDHC, 2-oxoglutarate dehydrogenase complex; Lip-AMP, lipoyl-AMP; LplA, lipoate-protein ligase A; PDHC, pyruvate dehydrogenase complex; TCA, tricarboxylic acid;