InterPro domain: IPR044725

CBS domains are small intracellular modules that pair together to form a stable globular domain [ 1 ]. Pairs of these domains have been termed a Bateman domain [ 2 ]. CBS domains have been shown to bind ligands with an adenosyl group such as AMP, ATP and S-AdoMet [ 3 ]. CBS domains are found attached to a wide range of other protein domains suggesting that CBS domains may play a regulatory role making proteins sensitive to adenosyl carrying ligands. The region containing the CBS domains in cystathionine-beta synthase is involved in regulation by S-AdoMet [ 4 ]. CBS domain pairs from AMPK bind AMP or ATP [ 5 ]. The CBS domains from IMPDH and the chloride channel CLC2 bind ATP [ 5 ].

This entry represents the CBS domain found in bacteria and plants proteins, including mitochondrial CBSX3 from Arabidopsis. CBSX3 interacts with and activates o-type thioredoxin (Trx-o2) Trx-o2, increasing its activity, which is known to play regulatory roles in the electron transport chain (ETC) complex II. This interaction regulates ROS generation in mitochondria and plays a key role in the modulation of plant development and growth [ 5 , 6 ].

1. Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase. Biochemistry 38, 4691-700
2. Bateman domains and adenosine derivatives form a binding contract. J. Clin. Invest. 113, 182-4
3. CBS domains form energy-sensing modules whose binding of adenosine ligands is disrupted by disease mutations. J. Clin. Invest. 113, 274-84
4. Regulation of human cystathionine beta-synthase by S-adenosyl-L-methionine: evidence for two catalytically active conformations involving an autoinhibitory domain in the C-terminal region. Biochemistry 40, 10625-33
5. CBSX3-Trxo-2 regulates ROS generation of mitochondrial complex II (succinate dehydrogenase) in Arabidopsis. Plant Sci 294, 110458
6. CBSXs are sensor relay proteins sensing adenosine-containing ligands in Arabidopsis. Plant Signal Behav 7, 664-7