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bioRxiv · 10.1101/2021.11.30.470528

Structural characterization of a MAPR-related archaeal cytochrome b5M protein

Teakel, S.·Marama, M.·Aragao, D.·Tsimbalyuk, S.·Forwood, J. K.·Cahill, M. A.
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Abstract

We recently reported that the membrane associated progesterone receptor (MAPR) protein family (mammalian members: PGRMC1, PGRMC2, NEUFC and NENF) originated from a new class of prokaryotic cytochrome b5 (cytb5) domain proteins, called cytb5M (MAPR-like). Relative to classical cytb5 proteins, MAPR and ctyb5M proteins shared unique sequence elements and a distinct heme binding orientation at an approximately 90 rotation relative to classical cytb5, as demonstrated in the archetypal crystal structure of a cytb5M protein (PDB accession number 6NZX). Here, we present the second crystal structure of an archaeal cytb5M domain (Methanococcoides burtonii WP_011499504.1, PDB:6VZ6). It exhibits similar heme-binding to the 6NZX cytb5M, supporting the deduction that MAPR-like heme orientation was inherited from the prokaryotic ancestor of the original eukaryotic MAPR gene.

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Teakel, S., Marama, M., Aragao, D., Tsimbalyuk, S., Forwood, J. K., Cahill, M. A.. 2021-11-30. Structural characterization of a MAPR-related archaeal cytochrome b5M protein. https://doi.org/10.1101/2021.11.30.470528

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