FIG. 5.

A CLUSTAL W alignment of a 30-amino-acid segment of the ICM large subunit (IcmA) of Methylibium petroleiphilum PM1 (ZP_00242470), with the corresponding sequences of the four closest BLAST matches using the complete IcmA sequence of strain PM1 as a query against the NCBI database (in descending order): Rhodobacter sphaeroides ATCC 17029 (EAP67072), Xanthobacter autotrophicus Py2 (EAS17594), Nocardioides sp. strain JS614 (EAO08692), and Roseovarius sp. strain 217 (EAQ26421) (for complete search results, see the supplemental material). For comparison, alignment with the corresponding ICM and MCM sequences of S. cinnamonensis (AJ246005) and P. shermanii (X14965), respectively, is also shown. Amino acids that are conserved in all sequences are indicated under the sequence by asterisk. Residues in boldface represent the reactive site position proposed to play an important role in substrate binding and reaction mechanism of both ICM and MCM (32, 39, 50).