Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Expression from promoter regions. Expression of lacZ, by β-galactosidase activity of various-sized promoter fragments (A and C), or nitrogenase activity, by acetylene reduction (B) from various promoter fragments or a nifSU deletion as shown in Fig. 1C. Nitrogenase is expressed as nmol of ethylene mg OD720−1 h−1. Strain JU467 is a promoterless lacZ fusion used to measure background β-galactosidase.
