Functional Analysis of Bacillus subtilis Genes Involved in the Biosynthesis of 4-Thiouridine in tRNA

• DOI: 10.1128/jb.00842-12
• Publication Date: 2012-07-07T05:42:15Z
• Authors: Lauren J. Rajakovich; John Tomlinson; Patricia C. Dos S...
• Keywords: Sulfurtransferase

ABSTRACT ThiI has been identified as an essential enzyme involved in the biosynthesis of thiamine and tRNA thionucleoside modification, 4-thiouridine. In Escherichia coli Salmonella enterica , acts a sulfurtransferase, receiving sulfur donated from cysteine desulfurase IscS transferring it to target molecule or additional carrier proteins. However, Bacillus subtilis most species Firmicutes phylum, lacks rhodanese domain that contains site responsible for sulfurtransferase activity. The lack gene encoding canonical presence short sequence these bacteria pointed mechanistic differences involving trafficking reactions both biosynthetic pathways. Here, we have carried out functional analysis B. thiI adjacent gene, nifZ desulfurase. Gene inactivation experiments indicate requirement NifZ 4-thiouridine, but not thiamine. vitro synthesis 4-thiouridine by NifZ, along with labeling experiments, suggests occurrence alternate transient transfer, thus obviating need domain. vivo complementation studies E. IscS- ThiI-deficient strains provide further support specific interactions between ThiI. These results are compatible proposal utilize mechanistically distinct mutually transfer reactions.