Catalyzes the hydroxylation of n-alkanes in the presence of a NADH-rubredoxin reductase and rubredoxin. It preferably hydroxylases long-chain-length alkanes with at least 12 carbon atoms. 2 H(+) + O2 + octane + 2 reduced [rubredoxin] = H2O + octan-1-ol + 2 oxidized [rubredoxin] Binds 2 Fe(3+) ions per subunit. Hydrocarbon metabolism; alkane degradation. Induced by AlkR and n-alkanes only in stationary phase. Repressed by oxidized alkane derivatives. Belongs to the fatty acid desaturase type 1 family. AlkB subfamily.