Tu JM, Zhou M, Haessner R, Plöscher M, Eichacker L, Scheer H, Zhao KH. Toward a mechanism for biliprotein lyases: revisiting nucleophilic addition to phycocyanobilin.
J Am Chem Soc 2010;
131:5399-401. [PMID:
19323460 DOI:
10.1021/ja9002348]
[Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Biliprotein lyases attach linear-tetrapyrrolic bilins covalently to apoproteins, which is a prerequisite for the assembly of phycobiliproteins into phycobilisomes, the light-harvesting complexes of cyanobacteria. On the basis of the addition of thiol and imidazole to phycocyanobilin, we propose a generalized lyase reaction mechanism. The adducts contain isomerized phycocyanobilin that can be transferred by the lyase to apoproteins by either back-isomerization, generating phycocyanobilin-containing proteins, or direct transfer, generating phycoviolobilin-containing proteins.
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