ARTICLE Received 4 Feb 2016 | Accepted 5 Oct 2016 | Published 18 Nov 2016 DOI: 10.1038/ncomms13446 OPEN An archaeal ADP-dependent serine kinase involved in cysteine biosynthesis and serine metabolism Yuki Makino1, Takaaki Sato1,2, Hiroki Kawamura1, Shin-ichi Hachisuka1,2, Ryo Takeno1, Tadayuki Imanaka2,3 & Haruyuki Atomi1,2 Routes for cysteine biosynthesis are still unknown in many archaea. Here we find that the hyperthermophilic archaeon Thermococcus kodakarensis generates cysteine from serine via O-phosphoserine, in addition to the classical route from 3-phosphoglycerate. The protein responsible for serine phosphorylation is encoded by TK0378, annotated as a chromosome partitioning protein ParB. The TK0378 protein utilizes ADP as the phosphate donor, but in contrast to previously reported ADP-dependent kinases, recognizes a non-sugar substrate. Activity is specific towards free serine, and not observed with threonine, homoserine and serine residues within a peptide. Genetic analyses suggest that TK0378 is involved in serine assimilation and clearly responsible for cysteine biosynthesis from serine. TK0378 homologs, present in Thermococcales and Desulfurococcales, are most likely not ParB proteins and constitute a group of kinases involved in serine utilization. 1 Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan. 2 JST, CREST, 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan. 3 Research Organization of Science and Technology, Ritsumeikan University, Noji-Higashi, Kusatsu 525-8577, Japan. Correspondence and requests for materials should be addressed to H.A. (email:
[email protected]). NATURE COMMUNICATIONS | 7:13446 | DOI: 10.1038/ncomms13446 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/ncomms13446 embers of the Archaea, which form the third domain Evaluation of established Cys biosynthesis pathways.