BIOCHEMISTRY Correction for “The Corynebacterium diphtheriae shaft pilin SpaA is built of tandem Ig-like modules with stabilizing isopeptide and disulfide bonds,” by Hae Joo Kang, Neil G. Paterson, Andrew H. Gaspar, Hung Ton-That, and Edward N. Baker, which appeared in issue 40, October 6, 2009, of Proc Natl Acad Sci USA (106:16967–16971; first published September 21, 2009; 10.1073/pnas.0906826106).
The authors note that, due to a printer's error, on page 16967, the keyword “mas spectromrtry” should instead have appeared as “mass spectrometry.” The online version has been corrected.